Notwithstanding the provisions of Kan. Stat. Ann. §§ 74-4913 to the contrary, any employee of a participating employer with an entry date of January 1, 1962, who became a member of the Kansas public employees retirement system on February 1, 1964, was first employed by said participating employer from April 7, 1933, to April 30, 1943, and was reemployed from November 10, 1943, to April 15, 1947, and again from March 7, 1949, to September 30, 1954, and again employed January 10, 1963, shall upon retirement be granted prior service credit for employment with said participating employer prior to entry date whether such employment was continuous or not. A prior service benefit shall be computed by using a prior service annual salary of four thousand two hundred dollars ($4,200).