<PAGE>   1
                                                                EXHIBIT 10.30(b)


                                    GUARANTY

        This GUARANTY, dated as of February 10, 1999, is made by AAMES FINANCIAL
CORPORATION, a corporation organized under the laws of the State of Delaware
("Guarantor"), in favor of LEHMAN COMMERCIAL PAPER INC., a corporation organized
under the laws of the State of New York ("Lehman").

        As an inducement to and in consideration for Lehman to enter into the
Amended and Restated Master Repurchase Agreement Governing Purchases and Sales
of Mortgage Loans dated as of the date hereof (the "Repurchase Agreement")
between Lehman and Aames Capital Corporation, a wholly-owned subsidiary of the
Guarantor ("Aames"), the Guarantor hereby unconditionally and irrevocably
guarantees the punctual payment and performance when due, whether at stated
maturity, by acceleration or otherwise, of all obligations of Aames now or
hereafter existing under the Repurchase Agreement (such obligations being the
"Obligations"), and agree to pay any and all expenses incurred by Lehman in
enforcing any rights under this Guaranty. This Guaranty is a guaranty of payment
and not of collection. Lehman shall not be required to exhaust any right to
remedy or take any action against Aames, any guarantor, any other person, any
collateral or any credit support.

        The Guarantor guarantees that the Obligations will be paid or performed
strictly in accordance with their terms. The liability of the Guarantor under
this Guaranty shall be absolute and unconditional irrespective of any defense
whatsoever available to Aames or a guarantor, including but not limited to the
following: (a) any lack of validity or enforceability or any Obligation or any
agreement or instrument related thereto; (b) any change in the time, manner or
place of payment or performance of, or in any term of, all or any of the
Obligations, or any other amendment or waiver of or any consent to the departure
from any Obligation or any agreement or instrument related thereto; (c) any
exchange, release or non-perfection of any collateral, or any release or
amendment or waiver of or consent to departure from any other guaranty, for all
or any of the Obligations; or (d) any law, regulation or order of any
jurisdiction affecting or purporting to affect any terms of any Obligation or of
any agreement or instrument relating thereto or any of Lehman's rights with
respect thereto (including, without limitation, any stay imposed by the Federal
bankruptcy laws).

        This Guaranty is a continuing guaranty and shall remain in full force
and effect until the Obligations have been paid in full.

        The Guarantor hereby waives promptness, diligence, notice of acceptance
and any other notice with respect to any of the Obligations or this Guaranty.
This Guaranty shall continue to be effective or be reinstated, as the case may
be, if any payment of any of the Obligations is rescinded or must otherwise be
returned by Lehman upon the insolvency, bankruptcy or reorganization of Aames or
otherwise, all as though such payment had not been made.

<PAGE>   2
        The Guarantor will not exercise any rights which it may acquire by way
of subrogation under this Guaranty, by any payment made hereunder or otherwise,
until all the Obligations shall have been paid in full. If any amount shall be
paid to the Guarantor on account of such subrogation rights at any time when all
the Obligations shall not have been paid in full, such amount shall be held in
trust for the benefit of Lehman and shall forthwith be paid to Lehman to be
applied to the Obligations, whether matured or unmatured, in accordance with the
terms of such Obligations and any related agreement or instrument.

        Any and all payments made by the Guarantor hereunder shall be made free
and clear of and without deduction from any and all present and future taxes,
levies, deductions, charges or withholdings and all liabilities with respect
thereof, excluding taxes imposed on Lehman's income and franchise taxes imposed
on Lehman by the jurisdiction under which Lehman is organized.

        All notices hereunder shall be in writing and sent or delivered:

        if to Lehman:

        c/o Lehman Commercial Paper Inc.
        3 World Financial Center
        New York, New York  10285
        Attention:  Fred Madonna

        if to the Guarantor:

        350 South Grand Avenue
        Los Angeles, California 90071
        Attention:

or to either party at such other address(es) as may be specified in a written
notice given in accordance herewith.

        This Guaranty shall be binding upon the Guarantor, its successors and
assigns, and shall inure to the benefit of and be enforceable by Lehman and its
successors, transferees and assigns.

        THIS GUARANTY SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE
LAWS (OTHER THAN CONFLICTS LAWS) OF THE STATE OF NEW YORK.





                                       2
<PAGE>   3

        IN WITNESS WHEREOF, the Guarantor has caused this Guaranty to be duly
executed and delivered by its duly authorized officers as of the date first
above written.



                                    AAMES FINANCIAL CORPORATION


                                    By:   /s/  David A. Sklar
                                       -----------------------------------------
                                       Name:
                                       Title: