The trustees referred to in section 11529 shall file with such insurer and with the commissioner a verified acceptance of their appointments and verified declarations that they will faithfully discharge their duties as such trustees. All dividends and other sums received by said trustees on the shares held by them, after paying the necessary expenses of executing their trust, shall be immediately repaid to such insurer for the benefit of all who are, or may become, policyholders of such insurer of the class or classes for whose benefit the stock of such insurer was acquired and entitled to participate in the profits thereof and shall be added to and become a part of the assets of such insurer.