If the majority of the members of a regional workforce development board vote to participate in this part, employees of a regional workforce development board who are eligible under section 7-425, and who are not members of the Municipal Employees’ Retirement Fund B shall become members thereof on July 1, 1998. Membership in any other retirement system shall terminate on said date. The members of a regional workforce development board shall arrange for termination of such systems, which arrangements shall include provision that the rights of members who retired prior to July 1, 1998, under such system shall not be affected and provision that any refunds of employee contributions made to such other retirement system shall be transferred to the Municipal Employees’ Retirement Fund B and the appropriate amount credited to the account of each transferring employee’s benefit. Each employee of the regional workforce development board shall pay his pro rata share of the actual cost of such transfer at no additional cost to the municipality or board.