ReMerger with Mentmore-Part 2

BIRKBY PLC
27 July 1999


Part 2

                                Appendix I
                                     
Conditions and further terms of the Offer
                                     
The Offer will comply with the rules and regulations of the London Stock
Exchange and the City Code, will be governed by English law and subject to
the jurisdiction of the English courts and will be subject to the
following conditions:

(a) valid acceptances being received (and not, where permitted,
    withdrawn) by 3.00pm on the first closing date of the Offer (or such
    later time(s) and/or date(s) as Mentmore Abbey may, subject to the
    rules of the City Code, decide) in respect of not less than 90 per
    cent (or such lesser percentage as Mentmore Abbey may decide) in
    nominal value of the Birkby Shares to which the Offer relates,
    provided that this condition will not be satisfied unless Mentmore
    Abbey (together with any of its wholly-owned subsidiaries) shall have
    acquired or agreed to acquire, whether pursuant to the Offer or
    otherwise, Birkby Shares carrying, in aggregate, more than 50 per
    cent of the voting rights then exercisable at a general meeting of
    Birkby including for this purpose, to the extent (if any) required by
    the Panel, any such voting rights attaching to any Birkby Shares that
    may be unconditionally allotted or issued before the Offer becomes or
    is declared unconditional as to acceptances whether pursuant to the
    exercise of any outstanding conversion or subscription rights or
    otherwise; and, for this purpose, (i) the expression 'Birkby Shares
    to which the Offer relates' shall be construed in accordance with
    Sections 428 to 430F of the Companies Act 1985 and (ii) shares which
    have been unconditionally allotted shall be deemed to carry the
    voting rights which they will carry upon issue;

(b) the passing at an Extraordinary General Meeting of Mentmore Abbey (or
    at any adjournment thereof) of such resolutions as may be necessary
    to approve and implement the Offer;

(c) the London Stock Exchange agreeing to admit to the Official List the
    New Mentmore Abbey Shares and such admission becoming effective in
    accordance with paragraph 7.1 of the Listing Rules of the London
    Stock Exchange or (if determined by Mentmore Abbey and subject to the
    consent of the Takeover Panel) agreeing to admit such shares to the
    Official List subject only to (i) the allotment of such shares and/or
    (ii) the Offer becoming or being declared unconditional in all
    respects;

(d) it having been established in terms reasonably satisfactory to
    Mentmore Abbey that it is not the intention of the Secretary of State
    for Trade and Industry to refer the Offer or any matter arising
    therefrom to the Competition Commission;

(e) no government or governmental, quasi-governmental, supranational,
    statutory or regulatory body, court, trade agency, association,
    institution or professional body or any other person or body in any
    jurisdiction (each a 'Third Party') having prior to the date when the
    Offer would otherwise become unconditional decided to take, institute
    implement or threaten, and there not continuing to be outstanding,
    any action, proceedings, suit, investigation, enquiry or reference,
    and no such Third Party having made, proposed or enacted, any
    statute, regulation, decision or order, or taken any other steps
    which would or might reasonably be expected to:

    (i)  make the Offer or its implementation or the acquisition by any
         member of the Mentmore Abbey Group of any shares in, or control
         of, Birkby, void, illegal or unenforceable or otherwise,
         directly or indirectly, restrain, prohibit, restrict or delay or
         impose additional materially adverse conditions or obligations
         with respect thereto, or otherwise challenge or interfere
         therewith;
    
    (ii) require or prevent the divestiture by any member or the Wider
         Birkby Group or the Wider Mentmore Abbey Group of all or any
         material part of their respective businesses, assets or property
         or impose any material limitation on the ability of any of them
         to conduct all or any part of their respective businesses or own
         all or any part of their respective assets or property to an
         extent which in each case would be material in the context of
         the Wider Birkby Group taken as a whole or the Wider Mentmore
         Abbey Group taken as a whole;
    
    (iii)impose any material limitation on the ability of any member
         of the Mentmore Abbey Group or the Wider Birkby Group to
         acquire, directly or indirectly, any rights of ownership of
         shares or other securities (or their equivalent) in any member
         of the Wider Birkby Group or on the ability of any member of the
         Wider Birkby Group or the Mentmore Abbey Group to hold or
         exercise effectively directly or indirectly any rights of
         ownership of shares or other securities (or their equivalent) in
         any member of the Wider Birkby Group held or owned by it or to
         exercise management control over any member of the Wider Birkby
         Group to an extent which is material in the context of the
         Birkby Group taken as a whole or, as the case may be, the
         Mentmore Abbey Group taken as a whole;
    
    (iv) require any member of the Mentmore Abbey Group or the Wider
         Birkby Group to offer to acquire any shares or other securities
         (or equivalent) in any member of the Wider Birkby Group owned by
         any third party;
    
    (v)  impose any material limitation on the ability of any member of
         the Mentmore Abbey Group or the Birkby Group to integrate all or
         any material part of its business with all or any material part
         of the business of any other member of the Mentmore Abbey Group
         or the Birkby Group; or
    
    (vi) otherwise adversely affect the business, profits or prospects of
         any member of the Wider Mentmore Abbey Group or the Wider Birkby
         Group to an extent which is material in the context of
         respectively the Mentmore Abbey Group taken as a whole or the
         Birkby Group taken as a whole;

    and all applicable waiting and other time periods during which any
    Third Party could decide to take, institute, implement or threaten
    any such action, proceeding, suit, investigation, enquiry or
    reference having expired, lapsed or been terminated;

(f) all necessary filings having been made, all appropriate waiting
    periods under any applicable legislation or regulations or any
    jurisdiction having expired, lapsed or been terminated and all
    statutory or regulatory obligations in any applicable jurisdiction
    having been complied with in each case in respect of the Offer and
    the acquisition, directly or indirectly, by any member of the
    Mentmore Abbey Group of any shares or other securities (or their
    equivalent) in, or control of, Birkby and all authorisations which in
    the reasonable opinion of Mentmore Abbey are necessary or appropriate
    in any jurisdiction in respect of the Offer having been obtained in
    terms and in a form reasonably satisfactory to Mentmore Abbey and all
    such authorisations which in the reasonable opinion of Mentmore Abbey
    are necessary or appropriate to carry on the business of any member
    of the Wider Birkby Group, having been obtained and remaining in full
    force and effect and there being no intimation or notice or an
    intention to revoke or not to renew the same;

(g) there being no provision of any arrangement, agreement, licence,
    permit, franchise or other instrument to which any member of the
    Wider Birkby Group is a party or by or to which any such member or
    any of their assets may be bound, entitled or be subject and which,
    as a result of the acquisition of the Birkby Shares or any of them by
    any member of the Mentmore Abbey Group, would or might reasonably be
    expected to result in:
    
    (i)  any monies borrowed by, or any other indebtedness, actual or
         contingent of, any such member being, or becoming capable or
         being declared, repayable immediately or prior to their stated
         maturity or the ability of such member to borrow money or incur
         any indebtedness being withdrawn or inhibited;
    
    (ii) the creation of any mortgage, charge or other security interest
         over the whole or any part of the business, property or assets
         of any such member or any such mortgage, charge or other
         security (whenever arising or having arisen) becoming
         enforceable;
    
    (iii)any such arrangement, agreement, licence, permit, franchise
         or instrument being terminated or adversely modified or any
         action of an adverse nature being taken or any adverse
         obligation arising thereunder;
    
    (iv) any assets of any member of the Wider Birkby Group being or
         falling to be disposed of or charged or any right arising under
         which any such asset or interest could be required to be
         disposed of or charged in each case other than in the ordinary
         course of business;
    
    (v)  the interests or business of any member of the Wider Birkby
         Group in or with any other firm or body or person, or any
         arrangements relating to such interest or business, being
         terminated or materially and adversely modified or affected;
    
    (vi) any member of the Wider Birkby Group ceasing to be able to carry
         on business under any name under which it presently does so; or
    
    (vii)the value of any member of the Wider Birkby Group or its
         financial or trading position or prospects being prejudiced or
         adversely affected;
    
    in each case which will or might reasonably be expected to have a
    material adverse effect on the Birkby Group taken as a whole;

(h) save as publicly announced by Birkby in this announcement, the Birkby
    Preliminary Results, or prior to this announcement (in relation to
    Birkby), no member of the Birkby Group having, since 31 March 1998,
    the date to which Birkby's last published audited accounts were
    prepared (other than for transactions solely between members of the
    Birkby Group) and save as publicly announced by Mentmore Abbey in
    this announcement, the Mentmore Abbey Preliminary Results or prior to
    this announcement (in relation to Mentmore Abbey) no member of the
    Mentmore Abbey Group having, since 30 April 1998, the date to which
    Mentmore Abbey's last published audited accounts were prepared (other
    than for transactions solely between members of the Mentmore Abbey
    Group):
    
    (i)  issued or authorised or proposed the issue of additional shares
         of any class, or securities convertible into, or rights,
         warrants or options to subscribe for or acquire, any such shares
         or convertible securities (save for options granted and for any
         Birkby Shares allotted upon exercise of options granted under
         the Birkby Share Option Schemes or options granted and Mentmore
         Abbey Shares allotted upon the exercise of options granted under
         the Mentmore Abbey Share Option Schemes) or redeemed, purchased,
         reduced or made any other change to any part of its share
         capital;
    
    (ii) declared, paid, made or proposed to declare, pay or make any
         bonus, dividend or other distribution in respect of shares;
    
    (iii)authorised or proposed or announced its intention to
         propose any merger or demerger or acquisition or disposal of
         assets (other than in the ordinary course of business) or shares
         in each case which would be material in the context of the
         Birkby Group as a whole or the Wider Mentmore Abbey Group taken
         as a whole as the case may be;
    
    (iv) issued or authorised or proposed the issue of any debentures or,
         other than in the ordinary course of trading, incurred or
         increased any indebtedness or contingent liability or become
         subject to any contingent liability which is material in the
         context of the Birkby Group taken as a whole or the Wider
         Mentmore Abbey Group taken as a whole as the case may be;
    
    (v)  disposed of or transferred, mortgaged or encumbered any material
         asset or any right, title or interest in any such asset (other
         than in the ordinary course of trading) in each case which would
         be material in the context of the Birkby Group as a whole or the
         Wider Mentmore Abbey Group taken as a whole as the case may be;
    
    (vi) entered into, or amended any existing contract or commitment so
         as to give rise to, any contract or commitment (whether in
         respect of capital expenditure or otherwise) which is of an
         unusual nature or which involves or could involve an obligation
         of a nature or magnitude which is material in the context of the
         Birkby Group taken as a whole or terminated any existing
         contract or commitment which is material in the context of the
         Birkby Group taken as a whole or the Wider Mentmore Abbey Group
         taken as a whole as the case may be;
    
    (vii)entered into any long term contract, reconstruction or
         amalgamation, otherwise than in the ordinary course of business,
         which is material in the context of the Birkby Group taken as a
         whole or the Wider Mentmore Abbey Group taken as a whole as the
         case may be;
    
    (viii)taken any corporate action or had any order made for its
         winding up (voluntary or otherwise), dissolution or
         reorganisation or for the appointment of a receiver,
         administrator, administrative receiver, trustee or similar
         officer of all or any of its assets and revenues;
    
    (ix) entered into or varied the terms of any service agreement with
         any of the directors of Birkby or the directors of Mentmore
         Abbey;
    
    (x)  made or agreed or consented to any significant change to the
         terms of the trust deeds constituting the pension schemes
         established for its directors and/or employees and/or their
         dependants or to the benefits which accrue, or to the pensions
         which are payable thereunder, or to the basis on which
         qualification for or accrual or entitlement to such benefits or
         pensions are calculated or determined, or to the basis upon
         which the liabilities (including pensions) of such pension
         schemes are funded or made, or agreed or consented to any change
         to the trustees involving the appointment of a trust corporation
         which would be material in the context of the Birkby Group taken
         as a whole or the Wider Mentmore Abbey Group taken as a whole as
         the case may be;
    
    (xi) entered into an agreement which will result in the restriction
         of the scope of the business of the Birkby Group and will have a
         material adverse effect on the Birkby Group taken as a whole or
         the Wider Mentmore Abbey Group taken as a whole as the case may
         be;
    
    (xii)waived or compromised any claim which is or may be material
         in the context of the Birkby Group taken as a whole or the Wider
         Mentmore Abbey Group taken as a whole as the case may be; or
    
    (xiii)entered into an agreement or commitment or passed any
         resolution with respect to any of the transactions or events
         referred to in this paragraph;
    
(i) save as publicly announced by Birkby in this announcement, the Birkby
    Preliminary Results, prior to the date of this announcement or in the
    audited accounts of Birkby for the financial period ended 31 March
    1998, the date to which Birkby's last published audited accounts were
    made up (in relation to Birkby) or (in relation to Mentmore Abbey)
    save as publicly announced by Mentmore Abbey in this announcement,
    the Mentmore Abbey Preliminary Results, prior to the date of the
    announcement or in the audited accounts of Mentmore Abbey for the
    financial period ended 30 April 1998 the date to which Mentmore
    Abbey's last published accounts were made up;
    
    (i)  there having been no adverse change in the business, financial
         or trading position or profits or prospects of Birkby or
         Mentmore Abbey or any other member of the Birkby Group or any
         other member of the Mentmore Abbey Group which would be material
         to the Birkby Group taken as a whole or the Mentmore Abbey Group
         taken as a whole as the case may be;
    
    (ii) no litigation, arbitration proceedings, prosecution or other
         legal proceedings to which any member of the Birkby Group or the
         Mentmore Abbey Group is or may become a party (whether as
         plaintiff or defendant or otherwise) and no investigation by any
         Third Party against or in respect of any member of the Birkby
         Group or the Mentmore Abbey Group having been instituted,
         threatened or announced by or against or remaining outstanding
         in respect of any member of the Birkby Group or the Mentmore
         Abbey Group which in any such case might be materially adverse
         to the Birkby Group taken as a whole or the Mentmore Abbey Group
         taken as a whole as the case may be;
    
    (iii)no contingent liability having arisen which would
         reasonably be expected materially and adversely to affect the
         Birkby Group taken as a whole or the Mentmore Abbey Group taken
         as a whole as the case may be.
    
(j)  Mentmore Abbey not having discovered in respect of Birkby and Birkby
     not having discovered in respect of Mentmore Abbey after the date of
     this announcement and prior to the Offer becoming unconditional in
     all respects that the financial or business information concerning
     the Birkby Group or the Mentmore Abbey Group which has been publicly
     disclosed at any time by any member of the relevant group either
     contains a material misrepresentation of fact or omits to state a
     fact necessary to make the information contained therein not
     materially misleading and which was not, if material in the context
     of the Birkby Group taken as a whole or the Mentmore Abbey Group
     taken as a whole as the case may be, corrected by a subsequent public
     announcement prior to the date of this announcement.
    
(k) Mentmore Abbey not having discovered after the date of this
    announcement and prior to the Offer becoming unconditional in all
    respects that:-
    
    (i)  any past or present member of the Birkby Group has not complied
         with all applicable laws of any relevant jurisdiction relating
         to environmental matters which non-compliance would give rise to
         any liability (whether actual or contingent) or cost on the part
         of any member of the Birkby Group which would be material to the
         Birkby Group taken as a whole;
    
    (ii) there has been an emission, disposal, discharge, deposit,
         spillage or leak of waste or hazardous or harmful substances on
         or about or from any property now or previously owned, occupied
         or made use of by any past or present member of the Birkby Group
         which would be likely to give rise to any liability (whether
         actual or contingent) or cost on the part of any member of the
         Birkby Group which would be material to the Birkby Group taken
         as a whole;
    
    (iii)there is or is likely to be any liability (whether actual
         or contingent) or requirement to make good, repair, reinstate or
         clean up any property now or previously owned, occupied, made
         use of or harmed by any past or present member of the Birkby
         Group which would be material to the Birkby Group taken as a
         whole.
    
Mentmore Abbey reserves the right to waive, in whole or in part, all or
any of conditions (d) to (k) inclusive provided that it will only waive
the conditions in paragraphs (h), (i) and (j) (insofar as they relate to
Mentmore Abbey) with the prior consent of Birkby such consent not to be
unreasonably delayed in the case of paragraphs (h), (i) and (j) and such
consent not to be withheld in the case of paragraph (h) unless the
relevant condition which has been breached is material in the context of
the Offer.  If the recommendation of the board of directors of Birkby is
withdrawn or if a competitive situation arises, Mentmore Abbey reserves
the right to waive all or any of the conditions in paragraphs (h), (i) and
(j) in whole or in part, in its absolute discretion and without any
requirement or obligation to seek or obtain the  prior consent of Birkby.

Mentmore Abbey shall be under no obligation to waive or treat as satisfied
any of conditions (d) to (k) inclusive by a date earlier than the latest
date specified below for the satisfaction thereof notwithstanding that the
other conditions of the Offer may at such earlier date have been waived or
fulfilled and that there are at such earlier date no circumstances
indicating that any such conditions may not be capable of fulfilment.  If
Mentmore Abbey is required by the Panel to make an offer for Birkby Shares
under the provisions of Rule 9 of the City Code, Mentmore Abbey may make
such alterations to the conditions, including that in condition (a) above,
as are necessary to comply with the provisions of that Rule.

The Offer will lapse unless the conditions set out above (other than
condition (a)) are fulfilled or (if capable of waiver) waived or, where
appropriate, have been determined by Mentmore Abbey in its reasonable
opinion to be or to remain satisfied no later than 21 days after whichever
is the later of the first closing date of the Offer and the date on which
the Offer becomes or is declared unconditional as to acceptances or, in
each case, such later date as the Panel may agree.

The Offer will lapse if the acquisition is referred to the Competition
Commission before 3.00 pm on the first closing date of the Offer or the
date when the Offer is declared or becomes unconditional as to
acceptances, whichever is the later.




                                Appendix II
                                     
               Financial Effects of Acceptance of the Offer
                                     

The following table sets out, for illustrative purposes only, and on the
bases and assumptions set out in the notes below, the financial effects of
acceptance of the Offer on capital value and gross income for an accepting
holder of one Birkby Share if the Offer becomes or is declared wholly
unconditional.


A.   Decrease in capital value

                                                        Notes         
                                                          
Market value of one Birkby Share                         (i)      319p
Cash consideration                                                 92p
Value of 1.7228 New Mentmore Abbey Shares - the share   (ii)      225p
consideration
Total value of consideration                                      317p
Decrease in capital value                                           2p
This represents a decrease of  approximately                      0.7%

B.   Decrease in gross income

                                                        Notes         
                                                          
Gross dividend income on one Birkby Share               (iii)    10.1p
Gross dividend from 1.7228 New Mentmore Abbey Shares -  (iv)      2.2p
the share consideration
Gross income from re-investment of cash consideration    (v)      5.1p
Total gross income from consideration                             7.3p
Decrease in gross income                                          2.8p
This represents a decrease of approximately                      27.7%

Notes:

(i)  The value of one Birkby Share in A above is based on the Closing
     Price of 319 pence for a Birkby Share on 26 July 1999, the last dealing
     day prior to this announcement.

(ii) The value of the share consideration in A, is based on the Closing
     Price of 130.5 pence for a Mentmore Abbey Share on 26 July 1999, the last
     dealing day prior to this announcement.

(iii)The gross dividend income on one Birkby Share is based on the
     aggregate of the interim dividend of 2.6p in respect of the year ended 31
     March 1999 and the final dividend of 6.5p in respect of the year ended 31
     March 1998 (as if both dividends had been paid post 6 April 1999, i.e. in
     line with the tax treatment afforded Mentmore Abbey's dividend payments)
     together with an associated tax credit of 10/90ths of the amount paid.

(iv) The gross dividend income from 1.7228 New Mentmore Abbey Shares is
     based on the aggregate of the interim and final dividends of 0.374p and
     0.781p respectively for Mentmore Abbey's year ended 30 April 1999 
     together with an associated tax credit of 10/90ths of the amount paid.

(v)  The gross income from the cash consideration has been calculated on
     the assumption that the cash is re-invested so as to yield 5.5 per cent.
     per annum, being the Government Securities Index average gross redemption
     yield for medium coupon UK gilts of maturities of up to five years as
     obtained from the Financial Times on 26 July 1999 (reflecting trading on
     23 July 1999), the last dealing date prior to the announcement of the
     Offer.

(vi) Save as disclosed in notes (iii) and (v) above, no account has been
     taken of any potential liability to taxation, or the making of a Mix and
     Match Election.




                               Appendix III
                                     
                                Definitions

The  following definitions apply throughout this announcement, unless  the
context requires otherwise:

'Abbey Storage'            Abbey Storage Limited;
                           
'Act'                      the Companies Act 1985, as amended;
                           
'BDM'                      Britannia Data Management Limited, the
                           records management business 49.9% owned by
                           Mentmore Abbey;
                           
'Birkby'                   Birkby PLC;
                           
'Birkby Group'             Birkby and its subsidiary and associated
                           undertakings;
                           
'Birkby Preliminary        the preliminary results of Birkby for the
Results'                   year ended 31 March 1999 to be published
                           today;
                           
'Birkby SAYE Scheme'       the Birkby PLC Savings Related Share Option
                           Scheme;
                           
'Birkby Share Option       the Birkby PLC Executive Share Option
Schemes'                   Scheme, the Birkby Number 1 Executive Share
                           Option Scheme, the Birkby Number 2
                           Executive Share Option Scheme, the Birkby
                           Number 3 Executive Share Option Scheme and
                           the Birkby SAYE Scheme;
                           
'Birkby Shareholders'      holders of Birkby Shares;
                           
'Birkby Shares' or 'Birkby the existing issued and fully paid ordinary
Share Capital'             shares of 5p each in Birkby and any further
                           such shares which are unconditionally
                           allotted or issued before the date on which
                           the Offer closes (or such earlier date,
                           (not being earlier than the date on which
                           the Offer becomes unconditional as to
                           acceptances, or if later the first closing
                           date of the Offer) as Mentmore Abbey may,
                           subject to the City Code, decide) as a
                           result of the exercise of options granted
                           under the Birkby Share Option Schemes;
                           
'Canada'                   Canada, its provinces and territories and
                           all areas subject to its jurisdiction and
                           any political subdivision thereof;
                           
'Cash Equivalent Occupancy actual revenue received from a Birkby site
Rate'                      as a percentage of the total revenue
                           achievable from that site as budgeted by
                           the directors of Birkby;
                           
'City Code'                the City Code on Takeovers and Mergers;
                           
'Closing Price'            the closing middle market price of Mentmore
                           Abbey Shares or Birkby Shares (as the case
                           may be), as derived from the Official List;
                           
'Completion of the Offer'  the close of business on the day on which
                           the Offer becomes or is declared
                           unconditional in all respects;
                           
'Directors'                the proposed directors of the Enlarged
                           Group, namely Nick Smith (Executive
                           Chairman), Kim Taylor-Smith (Chief
                           Executive), Clive Drysdale (Finance
                           Director), Richard Makowski (Managing
                           Director of BDM Strategic Alliance);
                           Michael Woodhead (Senior Non-executive
                           Director); Brian Howes (Non-executive
                           Director), and Anthony Lewis (Non-executive
                           Director);
                           
'Dresdner Kleinwort        Kleinwort Benson Securities Limited;
Benson'
                           
'EGM'                      the extraordinary general meeting of
                           Mentmore Abbey to approve, inter alia, the
                           Offer and any adjournment of that meeting;
                           
'Enlarged Group' or        Mentmore Abbey and its subsidiaries and
'Merged Group'             associated undertakings following
                           Completion of the Offer;
                           
'Form of Acceptance'       the form of acceptance, election and
                           authority for use by Birkby Shareholders in
                           connection with the Offer;
                           
'Iron Mountain'            Iron Mountain Incorporated;
                           
'Listing Particulars'      the listing particulars of Mentmore Abbey
                           to be posted to Birkby Shareholders and
                           Mentmore Abbey Shareholders in connection
                           with the Offer;
                           
'London Stock Exchange'    London Stock Exchange Limited;
                           
'Mentmore Abbey Group'     Mentmore Abbey and its subsidiary and
or 'the Group'             associated undertakings;
                           
'Mentmore Abbey Shares'    the existing issued and fully paid ordinary
                           shares of 10p each in Mentmore Abbey;
                           
'Mentmore Abbey'           Mentmore Abbey plc;
or 'the Company'
                           
'Mentmore Abbey            the preliminary results of Mentmore Abbey
Preliminary Results'       for the year ended 30 April 1999 to be
                           published today;
                           
'Mentmore Abbey Share      the Mentmore Abbey 1994 Executive Share
Option Schemes'            Option Scheme; the Mentmore Abbey 1996
                           Executive Share Option Scheme and the
                           Mentmore Abbey Sharesave Scheme 1992;
                           
'Merger'                   the combining of Mentmore Abbey and Birkby
                           to be effected by means of the Offer;
                           
'Mix and Match Election'   an election by a Birkby Shareholder to vary
                           the proportions of New Mentmore Abbey
                           Shares and cash receivable under the Offer
                           or, as the context requires, the
                           opportunity to make such an election;
                           
'New Mentmore Abbey        the ordinary shares of 10p each in Mentmore
Shares'                    Abbey to be issued in respect of the Offer;
                           
 'Offer'                   the recommended offer to be made by Singer
                           & Friedlander on behalf of Mentmore Abbey
                           to acquire the Birkby Share Capital and,
                           where the context admits, any subsequent
                           revision, variation, extension or renewal
                           thereof;
                           
'Offer Document'           the document to be addressed to Birkby
                           Shareholders containing the Offer;
                           
'Offer Period'             the period commencing on 24 June 1999 when
                           Mentmore Abbey and Birkby announced they
                           were in merger talks and ending at 3.00pm
                           on the first closing date of the Offer or,
                           if later, the date on which the Offer
                           becomes or is declared unconditional as to
                           acceptances or lapses;
                           
'Official List'            the London Stock Exchange Daily Official
                           List;
                           
'Singer & Friedlander'     Singer & Friedlander Limited;
                           
'Strategic Alliance' or    the strategic alliance relating to BDM
'BDM Strategic Alliance'   between Iron Mountain and Mentmore Abbey as
                           detailed in the Mentmore Abbey circular to
                           Shareholders dated 2 December 1998;
                           
'subsidiary undertaking',  shall be construed in accordance with the
'associated undertaking',  Act (but for this purpose ignoring
'undertaking'              paragraph 20 (1) (b) of Schedule 4A
                           thereof);
                           
'Takeover Panel'           the Panel on Takeovers and Mergers;
                           
'UK' or 'United Kingdom'   the United Kingdom of Great Britain and
                           Northern Ireland;
                           
'US' or 'United States'    the United States of America, its
                           territories and possessions, any state of
                           the United States of America and the
                           District of Columbia;
                           
'Wider Birkby Group'       Birkby and its subsidiary undertakings or
                           associated companies and any company, firm,
                           partnership or joint venture in which any
                           of them have an interest;
                           
'Wider Mentmore Abbey      Mentmore Abbey and its subsidiary
Group'                     undertakings or associated companies and
                           any company, firm, partnership or joint
                           venture in which any of them have an
                           interest.