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 November 1, 1969, and who was first employed by such employer on August 9, 1948, to January 11, 1965, shall upon retirement be entitled to receive prior service credit for such employment prior to January 1, 1971. The prior service benefit shall be computed by using a prior service annual salary of six thousand nine hundred twenty-six dollars ($6,926).