Notwithstanding the provisions of Kan. Stat. Ann. §§ 74-4915 to the contrary, a member of the system who first became a member on January 1, 1974, who had previously served with a participating employer in an elected position commencing May 1, 1936, to January 8, 1959, who served another participating employer as an elected official from January 8, 1959, to January 9, 1973, and whose date of birth is March 5, 1911, shall upon retirement have all prior service retirement benefits calculated using a prior service salary of $13,020.