a. Notwithstanding the provisions of sections 13-107 and 13-108 of this chapter, any person who from the thirtieth day of June, nineteen hundred twenty-eight, was or shall have been continuously in service paid for by the city which was not a basis for membership in this retirement system but which was a basis for participation in one or more retirement systems or pension funds supported wholly or partly by the city and who, within one year after discontinuing such service, became or becomes a member of this retirement system, shall be credited:
1. With all city-service rendered by such member before the first day of October, nineteen hundred twenty, and
2. With all service on or after such date and prior to the beginning of membership paid for by the city, which was the basis for participation by such member in one or more retirement systems or pension funds supported wholly or partly by the city but which was not a basis for participation in this retirement system, provided, that the crediting of any service on or after such date shall be only upon payment to the annuity savings fund in approximately equal installments within one year after membership begins, or at the beginning of membership in a lump sum, as he or she shall elect, of an amount equal to the amount that would have been in the annuity savings fund to his or her credit had such member been a contributing member during the period covered by such payment; provided, further, that such contributions shall be reduced by the amount of any and all contributions by him or her to such other retirement system or pension fund for the period covered by such payment which have not been and cannot be lawfully refunded to such member by such retirement system or pension fund.
b. (1) Notwithstanding any provision of sections 13-107 and 13-108 of this chapter or any provision or law to the contrary, any person who (a) began service as an employee of the city prior to July first, nineteen hundred thirty-eight and since such entry into service has served continuously as an employee of the city and/or the New York city transit authority and (b) is still in the employ of such authority, and (c) by reason of such service was eligible to receive benefits from the police pension fund, subchapter one, maintained by the city, and (d) because of eligibility for and receipt of such benefits was unable to become a member of this retirement system until the enactment of section 13-105 of this chapter, and (e) pursuant to such section, is now a member of this retirement system, his benefits under such police pension fund having been suspended pursuant to such section, may elect to obtain credit in this retirement system for all such service rendered from the time when his or her membership in such police pension fund began and prior to his or her attaining membership in this retirement system, by complying with the requirements set forth in paragraphs two and four of this subdivision.
(2) To obtain such service credit such member shall:
(a) Not later than December thirty-first, nineteen hundred sixty-eight (i) refund to such police pension fund the amount of all benefits received by him or her from such fund, together with interest thereon at the rate of four per centum per annum; and (ii) file with such police pension fund a request in writing that his or her contributions to such pension fund, including interest thereon at the rate of four per centum per annum be transferred by such pension fund to his or her credit in the annuity savings fund of this retirement system; and
(b) Pay into the annuity savings fund of this retirement system in the manner provided in paragraph four of this subdivision, an amount equal to the difference between:
(i) the amount obtained:
(1) by computing the sum which would have been accumulated in such annuity savings fund to his or her credit as of June thirtieth, nineteen hundred sixty-eight, if he or she had joined this retirement system on the date on which he or she became a member of such police pension fund and had then elected to contribute to this retirement system on the basis of a minimum retirement age of fifty-five years and a service-fraction of one one-hundredth, and had so contributed without election to cease contributing; and
(2) by subtracting from such amount computed pursuant to sub-item one of this item, the portion, if any, of such amount, which portion would constitute excess contributions subject to his withdrawal under any provision of this chapter which governs the right to withdraw excess contributions and which is or becomes applicable to such member at any time during the period herein allowed him or her for making such payment; and
(ii) the sum of (1) the amount of his or her contributions, plus interest thereon, transferred from such police pension fund to this retirement system pursuant to subparagraph (b) of paragraph three of this subdivision, and (2) the amount of the accumulated deductions to his or her credit in this retirement system as of June thirtieth, nineteen hundred sixty-eight.
(3) (a) Upon tender by such member to such police pension fund of the amount required to be refunded to such pension fund under the provisions of item (i) of subparagraph (a) of paragraph two of this subdivision, such pension fund shall accept such amount.
(b) Upon refund of benefits to such police pension fund and upon the filing of such request for transfer of such member's contributions to such pension fund, with interest at the rate of four per centum per annum thereon, pursuant to subparagraph (a) of paragraph two of this subdivision, such pension fund shall transfer such contributions and interest to this retirement system, which shall deposit such sum to such member's credit in the annuity savings fund.
(c) Upon request of such member, he or she shall be permitted to pay into the annuity savings fund of this retirement system, to his or her credit, the sums required to be so paid under the provisions of subparagraph (b) of paragraph two of this subdivision and paragraph four of this subdivision.
(4) Such member may effect the payment required in subparagraph (b) of paragraph two of this subdivision:
(a) in installments pursuant to an application duly executed by such member and filed with the retirement system, consenting that deductions be made from his or her compensation at double his or her normal rate per centum of contributions and paid to his or her credit into the annuity savings fund, until such payment is thereby completed; provided that such member may at any time during the period of such double deductions pay in a lump sum the total of the remaining sums to be so paid through deductions.
(b) by making such payment in a lump sum not later than December thirty-first, nineteen hundred sixty-eight.
(5) Upon completion of compliance by such member with the requirements of item (i) of subparagraph (a) of paragraph two of this subdivision, and upon transfer of such member's contributions, with interest thereon, from such police pension fund to this retirement system pursuant to subparagraph (b) of paragraph three of this subdivision, such police pension fund shall be discharged of all further obligations to such member.
(6) (a) Upon completion of compliance by such member with the requirements of paragraphs two and four of this subdivision, the period of service set forth in paragraph one of this subdivision, for which such member has thereby elected to obtain credit under this section, shall be credited as allowable city-service of such member, in addition to any other service creditable to him or her.
(b) Credit for such service obtained pursuant to this subdivision, including credit for service obtained pursuant to paragraph seven of this subdivision, shall be used in determining eligibility for benefits as well as amount of benefits.
(7) Notwithstanding any provision of the preceding paragraphs of this subdivision to the contrary, if such member shall pay a part of but not the entire sum required to be paid under subparagraph (b) of paragraph two of this subdivision and paragraph four of this subdivision, such member shall be credited, in addition to any other service creditable to him or her, with a portion of the total period of the allowable city-service to which he or she would be entitled under this subdivision upon full payment of such sum, which portion bears the same ratio to such total period as the total sum so paid by such member bears to the entire sum required to be paid under subparagraph (b) of paragraph two and paragraph four of this subdivision.