Notwithstanding the provisions of Kan. Stat. Ann. §§ 74-4913 to the contrary, an employee of a participating employer who became a member of the Kansas public employees retirement system on July 1, 1965, who was employed by another participating employer from January, 1929 through February, 1935, shall upon retirement be granted prior service credit for all service with a participating employer prior to January 1, 1962. The prior service benefit shall be computed by using a prior service annual salary of one thousand five hundred dollars ($1,500.00).