Every corporation organized or existing under Part 1 (commencing with Section 12000) in effect on December 31, 1979, is subject to and deemed to be organized under:
(a) The General Corporation Law (Division 1 (commencing with Section 100) of this title), if the corporation is organized with capital stock.
(b) The Nonprofit Mutual Benefit Corporation Law (Part 3 (commencing with Section 7110) of Division 2 of this title) if the corporation is organized without capital stock.