<PAGE>

                                                                    EXHIBIT 10.1

                       ASSIGNMENT AND ASSUMPTION AGREEMENT

               This ASSIGNMENT AND ASSUMPTION AGREEMENT (this "Agreement") is
made and entered into as of the 7th day of March 2003, by and between First
Reserve Fund IX, L.P., a Delaware limited partnership ("First Reserve") and
Dresser, Inc., a Delaware corporation (and its successors and assigns,
"Dresser"). Capitalized terms used, but not otherwise defined herein, shall have
the meanings ascribed to such terms in the Purchase Agreement (as defined
below).

               WHEREAS, First Reserve, Tokheim Corporation, an Indiana
corporation ("Parent"), Sunbelt Hose & Petroleum Equipment, Inc., a Georgia
corporation ("Sunbelt"), Tokheim RPS, LLC, a Delaware limited liability company
("RPS"), Tokheim Investment Corp., a Texas corporation ("TIC"), Gasboy
International, Inc., a Pennsylvania corporation ("Gasboy"), Tokheim Services,
LLC, an Indiana limited liability company ("Services") and Tokheim and Gasboy of
Canada Ltd., a corporation organized under the laws of Ontario, Canada ("TG
Canada") (Parent, Sunbelt, RPS, TIC, Gasboy, Services and TG Canada being
collectively referred to as "Sellers"), have entered into a Purchase Agreement
dated as of November 29, 2002, as modified by that certain letter agreement,
dated as of January 24, 2003, and as further modified by that certain letter
agreement, dated as of March 7, 2003 (as the same may be subsequently amended or
modified, the "Purchase Agreement"), pursuant to which Sellers have agreed to
sell the Acquired Assets and assign the Assumed Liabilities to Buyer and Buyer
has agreed to purchase the Acquired Assets and to assume and/or accept
assignment of the Assumed Liabilities from Sellers, on the terms set forth in
the Purchase Agreement;

               WHEREAS, in connection with the execution of the Purchase
Agreement, First Reserve deposited on December 2, 2002, with State Street Bank
and Trust Company, a Massachusetts trust company (the "Escrow Holder"), the
amount of $1,470,000 (the "Deposit") to be held by the Escrow Holder in
accordance with the Escrow Agreement, dated as of November 29, 2002 (as the same
may be amended from time to time, the "Escrow Agreement"), among First Reserve,
Sellers and the Escrow Holder; and

               WHEREAS, in accordance with Sections 4.7 and 8.12 of the Purchase
Agreement and Section 14(a) of the Escrow Agreement, First Reserve desires to
assign all of its rights, duties and obligations under the Purchase Agreement
and the Escrow Agreement to Dresser and Dresser desires to accept such
assignment and to assume and hereafter pay, perform or discharge all of First
Reserve's duties and obligations under the Purchase Agreement and the Escrow
Agreement, in the manner and subject to the terms and conditions set forth
herein.

               NOW, THEREFORE, in consideration of the foregoing and for other
good and valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the parties hereto agree as follows:

<PAGE>

                                    ARTICLE I

                     ASSIGNMENT AND ASSUMPTION OF AGREEMENTS

               Section 1.01   Assignment and Assumption of Purchase Agreement.

               (a)     First Reserve hereby assigns, conveys, delivers, grants,
sells and transfers to Dresser, and Dresser hereby accepts, all of First
Reserve's rights, title and interests in, to and under the Purchase Agreement.

               (b)     First Reserve hereby assigns and transfers to Dresser,
and Dresser hereby accepts and assumes, all of First Reserve's duties and
obligations in, to and under the Purchase Agreement. Dresser shall hereafter
pay, perform or discharge such duties and obligations in accordance with their
terms.

               (c)     Pursuant to this Section 1.01, Dresser shall henceforth
act as "Buyer" under the Purchase Agreement in all respects with all rights and
obligations appurtenant thereto.

               Section 1.02   Assignment and Assumption of Escrow Agreement.

               (a)     First Reserve hereby assigns, conveys, delivers, grants,
sells and transfers to Dresser, and Dresser hereby accepts, all of First
Reserve's rights, title and interests in, to and under the Escrow Agreement.

               (b)     First Reserve hereby assigns and transfers to Dresser,
and Dresser hereby accepts and assumes, all of First Reserve's duties and
obligations in, to and under the Escrow Agreement. Dresser shall hereafter pay,
perform or discharge such duties and obligations in accordance with their terms.

               (c)     Pursuant to this Section 1.02, Dresser shall henceforth
act as "Buyer" under the Escrow Agreement in all respects with all rights and
obligations appurtenant thereto.

               Section 1.03   Treatment of Deposit. In connection with the
mutual execution and delivery of this Agreement, an amount equal to the Deposit
(plus the Escrow Interest (as defined in the Escrow Agreement) as of the date of
payment) shall be payable to First Reserve by Dresser. Such amount shall be paid
in immediately available funds by wire transfer to such bank account as
designated in advance by First Reserve.

                                   ARTICLE II

                         REPRESENTATIONS AND WARRANTIES

               Section 2.01   Authority; Binding Effect.

               (a)     First Reserve. First Reserve has the requisite
organizational power and authority to execute and deliver and to perform its
obligations under this Agreement. The execution and delivery by First Reserve of
this Agreement and the performance of its obligations hereunder have been duly
authorized by all necessary organizational or other action on the part

                                        2

<PAGE>

of First Reserve. This Agreement has been duly executed and delivered by First
Reserve and, assuming the due authorization, execution and delivery of this
Agreement by Dresser, constitutes a valid and binding obligation of First
Reserve, enforceable against First Reserve in accordance with its terms, except
as the availability of equitable remedies may be limited by equitable principles
of general applicability.

               (b)     Dresser. Dresser has the requisite corporate power and
authority to execute and deliver and to perform its obligations under this
Agreement. The execution and delivery by Dresser of this Agreement and the
performance of its obligations hereunder have been duly authorized by all
necessary corporate or other action on the part of Dresser. This Agreement has
been duly executed and delivered by Dresser and, assuming the due authorization,
execution and delivery of this Agreement by First Reserve, constitutes a valid
and binding obligation of Dresser, enforceable against Dresser in accordance
with its terms, except as the availability of equitable remedies may be limited
by equitable principles of general applicability.

                                   ARTICLE III

                                FEES AND EXPENSES

               Section 3.01   Reimbursement of Fees and Expenses. Dresser shall
reimburse First Reserve promptly upon request for First Reserve's out-of-pocket
costs and expenses, including fees and expenses of counsel, incurred in
connection with the Contemplated Transactions (including such costs, expenses
and fees incurred by First Reserve in connection with or relating to the Gasboy
Assets and the Excluded Subsidiaries), the Purchase Agreement, the Escrow
Agreement and this Agreement. Such amounts shall be paid in immediately
available funds by wire transfer to such bank account as designated in advance
by First Reserve.

               Section 3.02   Assumption of Fees and Expenses. First Reserve
hereby assigns and transfers to Dresser, and Dresser hereby accepts and assumes,
all of First Reserve's duties and obligations to pay the costs and expenses,
including fees and expenses of counsel, incurred by First Reserve in connection
with the Contemplated Transactions (including such costs, expenses and fees
incurred by First Reserve in connection with or relating to the Gasboy Assets
and the Excluded Subsidiaries), the Purchase Agreement, the Escrow Agreement and
this Agreement. Dresser shall hereafter pay, perform or discharge such duties
and obligations in accordance with their terms.

                                   ARTICLE IV

                                    INDEMNITY

               Section 4.01   Indemnification. Dresser shall indemnify and hold
harmless First Reserve and each of its partners, directors, officers, employees,
representatives, agents, affiliates and controlling persons (collectively, the
"Indemnified Persons") from and against any and all losses, claims, damages,
liabilities or expenses (including, without limitation, any legal or other
expenses reasonably incurred by an Indemnified Person in connection with
defending or investigating any such action or claim) to which any Indemnified
Person may become subject

                                        3

<PAGE>

under any applicable federal or state law, or otherwise, related to or arising
out of the Contemplated Transactions or any of the other transactions
contemplated by the Purchase Agreement, the contemplation of the proposed
purchase of certain of the Excluded Subsidiaries and the Gasboy Assets, the
Purchase Agreement or the Escrow Agreement, including performance of financial
advisory and other services for Dresser in connection therewith, except to the
extent that any such loss, claim, damage, liability or expense is held in a
final non-appealable judgment by a court of competent jurisdiction to have
primarily resulted from such Indemnified Person's bad faith, willful misconduct
or gross negligence.

                                    ARTICLE V

                                  MISCELLANEOUS

               Section 5.01   General. Notwithstanding any other provisions of
this Agreement to the contrary, nothing contained herein shall in any way
supersede, modify, replace, amend, change, rescind, waive, exceed, expand,
enlarge or in any way affect the provisions or any of the rights, obligations
and remedies of Buyer or Sellers set forth in the Purchase Agreement, the Escrow
Agreement or the other agreements attached thereto or delivered in connection
therewith.

               Section 5.02   Amendments and Waivers.

               (a)     Any provision of this Agreement may be amended or waived
if, but only if, such amendment or waiver is in writing and is signed, in the
case of an amendment, by each party to this Agreement, or in the case of a
waiver, by the party against whom the waiver is to be effective.

               (b)     No failure or delay by any party in exercising any right,
power or privilege hereunder shall operate as a waiver thereof nor shall any
single or partial exercise thereof preclude any other or further exercise
thereof or the exercise of any other right, power or privilege. The rights and
remedies herein provided shall be cumulative and not exclusive of any rights or
remedies provided by law.

               Section 5.03   Further Assurances. From time to time after the
date hereof, and without any further consideration, each of the parties to this
Agreement shall execute, acknowledge and deliver all such additional
instruments, notices and other documents, and shall do all such other acts and
things, all in accordance with applicable law, as may be necessary or
appropriate to more fully and effectively carry out the purposes and intent of
this Agreement.

               Section 5.04   Successors and Assigns. The provisions of this
Agreement shall be binding upon and inure to the benefit of the parties hereto
and their respective permitted successors and assigns; provided that no party
may assign, delegate or otherwise transfer any of its rights or obligations
under this Agreement without the prior written consent of the other party
hereto; provided, however, that Dresser may assign its rights, duties and
obligations under the Purchase Agreement to DI Canada Inc.

               Section 5.05   Governing Law. This Agreement, and any disputes
arising hereunder or controversies related hereto, shall be governed by, and
construed in accordance

                                        4

<PAGE>

with, the laws of the State of New York, except for principles of conflicts of
law thereof which would require application of the laws of another jurisdiction.

               Section 5.06   Counterparts; Third Party Beneficiaries. This
Agreement may be signed in any number of counterparts, each of which shall be an
original, with the same effect as if the signatures thereto and hereto were upon
the same instrument. This Agreement shall become effective when each party
hereto shall have received a counterpart hereof signed by the other party
hereto. No provision of this Agreement is intended to confer upon any person
other than the parties hereto any rights or remedies hereunder.

               Section 5.07   Captions.  The captions herein are included for
convenience of reference only and shall be ignored in the construction or
interpretation hereof.

               Section 5.08   Arbitration.

               (a)     Any dispute, controversy, or claim arising out of or
relating to any provision of this Agreement or the interpretation,
enforceability, performance, breach, termination, or validity hereof, including,
without limitation, this arbitration clause, shall be solely and finally settled
by binding arbitration in New York, New York in accordance with the rules of the
American Arbitration Association as modified by the provisions of this Section
5.08. The arbitration shall be conducted by a panel of three arbitrators, to be
selected in the following manner: each party shall select one arbitrator within
30 days from the date of receipt of the demand to commence arbitration. If one
or both of the parties fail to nominate an arbitrator, the American Arbitration
Association shall have the power to select an arbitrator on the party's behalf.
Within 30 days after the appointment of the last of the two arbitrators, the
selected party arbitrators shall choose a third arbitrator to serve as the
neutral chair of the panel. An award rendered in connection with an arbitration
pursuant to this Section 5.08 shall be final and binding upon the parties, and
any judgment upon such an award may be entered and enforced in any court of
competent jurisdiction. The arbitral panel may, at the request of a party, order
provisional or conservatory measures (including, without limitation, preliminary
injunctions to prevent breaches hereof) and the parties shall be able to enforce
the terms and provisions of such orders in any court having jurisdiction.

               (b)     Each party agrees to facilitate the arbitration by: (i)
making available to each other and to the arbitrators for inspection and
extraction all documents, books, records and personnel under their control as
the arbitrators shall determine to be relevant to the dispute; (ii) conducting
arbitration hearings to the greatest extent possible on successive, contiguous
days; and (iii) observing strictly the time periods established by the rules of
the American Arbitration Association or by the arbitrators for the submission of
evidence and briefs.

               (c)     The existence of arbitration held hereunder, and all
papers, documents or evidence, whether written or oral, filed with or presented
to the arbitrator shall be deemed by the parties and the arbitrator to be
confidential information. No party, expert or arbitrator shall disclose in whole
or in part to any other Person the fact that an arbitration hereunder has been
commenced, is ongoing or has been decided, or any confidential information
submitted by any other Person in connection with any arbitration proceedings,
except to the extent (i) required by law or regulation, (ii) reasonably
necessary to assist counsel in the arbitration or preparation for

                                        5

<PAGE>

arbitration of the dispute, (iii) that such "confidential" information was
previously or subsequently becomes known to the disclosing party without
restrictions on disclosure, was independently developed by such disclosing party
or becomes publicly known through no fault of the disclosing party, or (iv) to
enforce any award hereunder or the terms hereof. Confidential information may be
disclosed to attorneys, parties, and "qualified outside experts" requested by
any party's counsel to furnish technical or expert services or to give testimony
at the arbitration proceedings.

               (d)     To the extent this Section 5.08 is deemed a separate
agreement, independent from this Agreement, Sections 3.01, 3.02, 5.05 and 5.09
are incorporated in this Section 5.08 by reference.

               Section 5.09   Notices. Unless otherwise provided herein, any
notice, tender, or delivery to be given hereunder by a party to the other party
may be effected by personal delivery in writing, or by registered or certified
mail, postage prepaid, return receipt requested, and shall be deemed
communicated as of the date of mailing. Mailed notices shall be addressed as set
forth below, but either party may change its address by written notice in
accordance with this paragraph.

               (a)     If to First Reserve:

                              First Reserve Corporation
                              1801 California Street, Suite 4110
                              Denver, Colorado 80202
                              Telecopy:  (303) 382-1275
                              Attention:  Thomas R. Denison

               (b)     If to Dresser:

                              Dresser, Inc.
                              15455 Dallas Parkway, Suite 1100
                              Addison, Texas 75001
                              Telecopy:  (972) 361-9883
                              Attention:  Frank P. Pittman

               Section 5.10   Notification under Purchase Agreement and Escrow
Agreement. Promptly upon the execution and delivery of this Agreement, the
parties shall deliver notices to Sellers and the Escrow Holder in accordance
with the terms of the Purchase Agreement and Escrow Agreement, as the case may
be, informing such parties of the assignments effected pursuant to this
Agreement.

                        (Last page before signature page)

                                        6

<PAGE>

               IN WITNESS WHEREOF, the parties hereto have caused this
Agreement to be duly executed and delivered in its name and on its behalf as of
the date first above written.

                                        First Reserve Fund IX, L.P.

                                        By:  First Reserve GP IX, L.P.,
                                             its General Partner

                                        By:  First Reserve GP IX, Inc.,
                                             its General Partner

                                        By:
                                             -----------------------------------
                                             Name:  Thomas R. Denison
                                             Title: Managing Director

                                        Dresser, Inc.

                                        By:
                                             -----------------------------------
                                             Name:  James A. Nattier
                                             Title: Executive Vice President and
                                                    Chief Finacial Offier

                                        7