Any municipal employee who is a member of the Municipal Employees’ Retirement Fund and who accepts employment with another municipality in a department which, on the date he commences employment participates or, within two years thereafter, elects to participate in said fund shall be credited for retirement purposes with his entire period of service, as defined in section 7-425, with all municipalities which are members of said fund, provided, if he had withdrawn his contributions from the fund, he shall not receive credit for such prior employment in the computation of his eventual retirement allowance unless the withdrawn contributions plus interest, if any, have been repaid with additional interest at a rate to be determined by the commission. When a member has obtained credit for prior service in another municipality, and the department in which he so served has subsequently been withdrawn from the fund, such member may, upon request to the commission, withdraw the total of all contributions made during such prior service, and such credit for prior service shall thereupon be withdrawn. The withdrawal of such contributions shall include five per cent interest credited in accordance with the provisions of section 7-440. The Retirement Commission may make regulations as to such matters relating to such transfers of employment as the Retirement Commission finds necessary for the uniform and equitable administration of this section, having regard to the welfare of transferring employees and the interests of the municipalities.