The credit for prior service to be granted local members and the benefits pertaining thereto, shall be established by contract between the board and the governing body of the agency. Benefits on account of each year of credited prior service shall be in the form of a percentage of either of the following:
(a) The final compensation of local safety members.
(b) The final compensation of a local miscellaneous member who retires after December 1, 1969, whether or not the contracting agency has elected to be subject to the provisions of this subdivision.
The percentages shall not exceed the analogous percentages applicable to the members’ current service, and shall be uniform for all local safety members, according to age at entry into the service of the contracting agency, if the member is entitled to credit for prior service, or age at entry into this system, if the member is not so entitled, and uniform for all local miscellaneous members regardless of age at entry.