Notwithstanding the provisions of Kan. Stat. Ann. §§ 74-4913 to the contrary, any employee of a participating employer who became a member of the Kansas public employees retirement system on July 1, 1966, following the employer’s entry date January 1, 1962, and who was first employed by said employer July 1, 1965, and who was employed by another participating employer having an entry date of January 1, 1967, from July 5, 1955, through June 5, 1965, shall upon retirement be granted service credit for all service prior to July 1, 1965. The prior service benefit shall be computed by using a prior service annual salary of seven thousand three hundred dollars ($7,300).