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 said employer on June 8, 1970, and who was employed by another participating employer from January, 1949 to January, 1961; 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 July 1, 1970 upon the payment of appropriate employer and employee contributions, shall be entitled to receive participating service credit for employment with his participating employer from date of membership. Said employee shall also be granted prior service credit with all participating employers for all service prior to January 1, 1962. Upon attainment of membership by the provisions of this act, such employee and his participating employer shall thereafter be governed by the provisions of the Kansas public employees retirement act. The prior service benefit shall be computed by using a prior service annual salary of five hundred eighty-eight dollars ($588.00).