No administrator shall act as such without a written agreement between the administrator and the insurer, and such written agreement shall be retained as part of the official records of both the insurer and the administrator for the duration of the agreement and five years thereafter. Such written agreement shall contain provisions which include the requirements of Sections 1759.2 to 1759.8, inclusive, except insofar as those requirements do not apply to the functions performed by the administrator.
Where a policy is issued to a trustee or trustees, a copy of the trust agreement and any amendments thereto shall be furnished to the insurer by the administrator and shall be retained as part of the official records of both the insurer and the administrator for the duration of the policy and five years thereafter.