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 January 13, 1964 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 of February 1, 1964, upon the payment of appropriate employer and employee contributions, and shall be entitled to receive participating service credit for employment with said participating employer from said date of membership. 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.