Notwithstanding the provisions of Kan. Stat. Ann. §§ 74-4911 and 74-4913 to the contrary, an employee of a participating employer who was first employed by a participating employer on January 14, 1935 through January 31, 1940, and who was employed by a participating employer from 1943 until 1949 and 1953 until 1957 and who is employed by a participating employer on the effective date of this act, shall be an eligible member of the Kansas public employees retirement system as of September 1, 1965, upon the payment of appropriate employer and employee contributions, and shall be entitled to receive participating service credit from date of membership. Upon attainment of membership by the provisions of this act, such employee shall receive prior service credit for all service with all participating employers prior to January 1, 1962. The prior service benefit shall be computed by using a prior service annual salary of seven thousand six hundred dollars ($7,600).