Any person who is a member under Section 8.568 on February 1, 1970, and who was employed in the uniformed force of the Underwriters’ Fire Patrol of San Francisco prior to becoming such a member shall have the right to elect to make contributions pursuant to this section and to receive credit as service under the Retirement System for all or any part of the time he was so employed.
Said election shall be made in writing on a form provided by the Retirement System and filed with the retirement board within 90 days after February 1, 1970.
Any such member who elects to make contributions and receive such credit shall contribute to the retirement fund an amount equal to the sum of:
contributions computed by applying the rate of contribution applicable to him on the date he elected to receive credit for such service to the monthly compensation earnable by him on said date multiplied by the number of months of such service for which he has elected to receive credit; and
interest on the unpaid balance of said contributions, commencing on the date of the member’s election to make such contributions, at the rate of interest currently being used from time to time under the Retirement System.
Payment of the contributions required by this section shall be made in a lump sum or by installment payments. Installment payments shall be made at times and in a manner fixed by the retirement board, provided that the period for completion of such payments shall not extend beyond the effective date of the member’s retirement.
Upon completion of payment of contributions in the amount specified in this section, the member shall be credited with service under the Retirement System in an amount equal to the service for which he has elected to receive credit pursuant to this section. The service with which the member is so credited shall be credited as current service.