This Part shall not affect, or in any way change, any of the provisions, conditions, rules, regulations or the administration of any pension plan or system which was adopted and is being administered by any municipality at the time this Part becomes effective, nor shall it affect or change any of the requirements as to age or length of service or maximum pension payments of any pension plan or system which was adopted and is being administered by any municipality at such time.
La. Consolidated Public Retirement § 11:3856