Notwithstanding the provisions of Kan. Stat. Ann. §§ 74-4911 and 74-4913 to the contrary, an employee who became a member of the Kansas public employees retirement system on February 1, 1976, and who is employed by a participating employer on the effective date of this act, shall, upon the payment of appropriate employer and employee contributions, be entitled to receive participating service credit for employment with his or her participating employer for the period January 1, 1965, until February 1, 1976. Such employee shall also be granted a prior service credit from January 10, 1955, until December 31, 1964. The prior service benefit shall be computed by using a prior service annual salary of four thousand six hundred ninety-two dollars ($4,692).