In this section, “federal act” means: The federal Self-Employed Individuals Tax Retirement Act of 1962; or The federal Employee Retirement Income Security Act of 1974. A savings bank may act as trustee of a plan under either federal act, as provided in this section. A savings bank may: Accept a trust under a plan that: Constitutes a qualified plan under a federal act and the rules and regulations adopted under it; and Requires the exclusive investment of trust funds in deposits of a mutual savings institution; and Continue as trustee of a plan that is determined not to be or ceases to be a qualified plan, if, when the savings bank accepted the trust, the savings bank judged the plan to be a qualified plan. A savings bank that is acting as trustee of a plan under a federal act: May integrate the trust funds with its other deposits; and Shall keep appropriate, detailed records of all transactions in which it engages as trustee.