In accordance with the authority provided by chapter 1166 of the Laws of 1971, a member of the New York State employees' retirement system or the New York state policemen's and firemen's retirement system who is entitled to purchase service credit for certain World War II duty pursuant to the provisions of section 41(k) and section 341(k) of the Retirement and Social Security Law, may purchase, on or after April 1, 1971, all or any portion of such service credit with any excess contributions that may be credited to the member's annuity savings fund. Upon proper application by the member on a form prepared by the Comptroller, a transfer will be made from such excess contributions in the annuity savings fund to required contributions in the annuity savings fund, and to the pension accumulation fund, in such proportions as are required by section 41(k)(2) and section 341(k)(2) of the Retirement and Social Security Law for the purchase of such service credit. In the event that the member's annuity savings fund is not credited with sufficient excess contributions to provide for the purchase of all of the member's purchasable World War II service credit, those excess contributions that are available may be transferred in proportional shares as set forth above to purchase the maximum amount of service credit purchasable with such funds.