Every corporation organized or existing under Part 3 (commencing with Section 10200) of Division 2 in effect on December 31, 1979, is subject to and deemed to be a nonprofit public benefit corporation organized for charitable purposes under Part 2 (commencing with Section 5110) of the Nonprofit Corporation Law (Division 2 (commencing with Section 5000) of this title) except if the corporation is organized primarily or exclusively for religious purposes, in which case it is subject to and deemed to be a nonprofit religious corporation under Part 4 (commencing with Section 9110) of the Nonprofit Corporation Law.