Any city of the first class may, by ordinance, provide for the payment of retirement benefits to employes who were separated from city employment on or before January 1, 1963, and who become eligible to receive social security benefits, without reduction by reason of any social security benefit earned in covered municipal employment, and may provide that such employes shall be entitled to receive the full amount of the retirement benefits earned by them in municipal employment.
53 P.S. § 13448