Such insurer, after mutualization, shall be a continuation of the original insurer, and such mutualization shall not affect such insurer’s certificate of authority nor existing suits, rights or contracts except as provided in said plan for the acquisition of the outstanding shares of the capital stock of such insurer, approved as provided in this chapter. Such insurer, after mutualization, shall exercise all the rights and powers and perform all the duties conferred or imposed by law upon insurers writing the classes of insurance written by it, and to protect rights and contracts existing prior to mutualization, subject to the effect of said plan. The board of directors of such insurer, prior to mutualization, may adopt amendments to its bylaws to take effect upon mutualization.