All securities purchased by the trustor for deposit in trust and all money received from the trustor for deposit in trust shall be placed in trust with a trustee within 30 days of their receipt by the funeral establishment pursuant to a trust agreement executed by the funeral establishment, the trustor and trustee which shall provide that the trustee shall hold the money or securities in trust for the purposes for which deposited and that the trustee, upon the signature of a majority of such trustees, shall deliver the corpus of the trust to the funeral establishment upon the filing of a certified copy of the death certificate or other satisfactory evidence of the death of the beneficiary, together with satisfactory evidence that the funeral establishment has furnished the merchandise and services, provided, however, that (1) in the case of a trust agreement between any of the trustees set forth in Section 7736 and a recipient of public assistance, under the provisions of subdivision (a) of Section 11158 or paragraph (1) of subdivision (e) of Section 12152 of the Welfare and Institutions Code, and provided the value limitations of those sections are not exceeded, such trust agreement may further provide that it is irrevocable, and (2) in all other cases such trust agreement shall further provide that at any time before the funeral establishment has furnished the merchandise and services provided for in the contract the trustor or the legally appointed representative may in writing demand and receive the return of the corpus of the trust, together with any income accrued in the trust, less the revocation fee provided for in Section 7735; provided, however, that if and when the trustor becomes otherwise eligible, or in order to become eligible, for public social services, as provided in Division 9 (commencing with Section 10000) of the Welfare and Institutions Code, he or she may agree, at his or her option, that the trust shall be irrevocable in order to avail himself or herself of the provisions of Section 11158 or Section 12152 of the Welfare and Institutions Code. The delivery of the corpus of the trust and the accumulated income to the funeral establishment performing the services, trustor or beneficiary pursuant to the terms of this article and the trust agreement herein referred to, shall relieve the trustee of any further liabilities with regard to those funds or income therefrom.