N.J. Stat. § 43:13-22.16
All employee members of the existing pension funds aforesaid, who become members of the city employees' retirement system provided by this act, shall be given credit for pension purposes hereunder and for all services rendered to the city prior to the effective date of this act; provided, however, that in case any such employee had heretofore agreed, under the provisions of the 3 statutes aforesaid, to pay for any part or all of such services rendered to the city prior to the effective date of this act, then the transfer of such employees' membership into the retirement system created hereby shall include the transfer to this system of all the conditions and obligations of such prior agreement, not inconsistent with this act, made by such employee; and such employee shall be deemed to agree and consent to the transfer to the system of such conditions and obligations until the said conditions and the provisions of this act have been fully complied with.
N.J.S. § 43:13-22.16