(a) Any member of fund B of the municipal employees’ retirement system, who, prior to such member’s date of employment with a municipality that is participating in said fund B, served in any branch of the armed forces of the United States during the times set forth in § 27-103 shall be credited with the period of such service to the extent that such member makes contributions to said fund for all or any part of the period of such service, except that any veteran who becomes a member on or after October 1, 1984, shall not receive credit for such war service if such member has received or is entitled to receive any retirement allowance for the same years of service from the federal government. Such contributions shall be computed at a rate of two per cent of such member’s first year’s salary as such employee, with interest at five per cent per annum, payable within one year of such employment, or on or before January 1, 1992, whichever is later, provided such contributions are made prior to the date of retirement. The period of such service for which contributions to said fund are made shall be counted for the purpose of computing the amount of such member’s retirement allowance, provided such member shall have completed five years of continuous service or fifteen years of active aggregate service with a participating municipality or shall be retired prior thereto due to disability incurred in the course of employment. Any member who purchases credit pursuant to this section and who later receives a retirement allowance for permanent and total disability under this part shall, upon written request, be refunded all such contributions paid under this section, provided such military service credit did not serve to increase the amount of disability retirement benefits for which such member was eligible.

(b) Notwithstanding the provisions of subsection (a) of this section, the municipal employer of any member who applies on or after July 1, 1986, for such military service credit shall pay all contributions required under said subsection which are attributable to that portion of the member’s military service time during which he was a prisoner of war, provided such member submits with his application for such credit sufficient proof from the United States Department of Veterans Affairs that he is a former prisoner of war. Any municipal employer which pays the contributions required under this subsection for a member who later receives a retirement allowance for permanent and total disability under this part shall, upon its written request, be refunded all such contributions paid under this subsection, provided such military service credit did not serve to increase the amount of disability retirement benefits for which the member was eligible.