Every retirement allowance payable to or on account of a member who retired under the provisions of Section 8.509 (formerly Section 165.2 of the Charter of 1932) on or after July 1, 1947, and prior to April 1, 1966, is hereby increased for time commencing on the effective date of this section, hereby designated as the first day of the month next following ratification by the State Legislature, to the amount it would have been if such allowance had been computed, on the date such member's retirement allowance was first effective, as if "average final compensation" were defined as the average monthly compensation earned by a member during any three consecutive years of credited service in the Retirement System in which his average compensation is the highest.
This section does not give any person retired under the provisions of said Section 8.509, or his successors in interest, any claim against the City and County for any increase in any retirement allowance paid or payable for time prior to the effective date of this section.
Any increase in any retirement allowance resulting from the calculation provided in this section shall be disregarded in connection with any adjustment of retirement allowances pursuant to the provisions of Section 8.526 (formerly Section 164.1 of the Charter of 1932).