It is the intent of this act to permit cities of the third class to adopt a new Municipal Officers and Employes Retirement System, and does not affect the provisions of the act of June twenty-third, one thousand nine hundred thirty-one (Pamphlet Laws, nine hundred thirty-two), Article forty-three, sections four thousand three hundred forty to four thousand three hundred fifty-three, inclusive, or existing firemen and policemen pension systems.
53 P.S. § 42015