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 February 1, 1966, and who was employed by another participating employer from January 13, 1941 until November 28, 1957, 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 four thousand two hundred ninety-six dollars ($4,296.00).