Notwithstanding the provisions of Kan. Stat. Ann. §§ 74-4913 to the contrary, any county employee who first became a member of the Kansas public employees retirement system on January 1, 1963, and who was first employed by said county on September 20, 1961, who was employed by another participating employer from January 1, 1924, to August 1, 1942, and from December 1, 1948, to July 1, 1949, and from April 1, 1952, to March 1, 1959, and by another participating employer from January 13, 1945, to April 17, 1948, shall upon retirement be granted prior service credit for service with all participating employers prior to January 1, 1962.