(a) Since he last became a member, and

(b) Prior to the completion of twenty-five years of total service in regional state park police service, and

(c) Toward which he and his employer have contributed under this section, plus 4. An additional pension of one-fiftieth of his final average salary, multiplied by the number of years of total service in regional state park police service prior to April first, nineteen hundred forty-nine. This pension shall be payable only if such member has had one or more years of service as a member. The computation of this pension shall be subject to the further conditions that:

(a) The service rendered prior to April first, nineteen hundred forty-nine, shall be limited so that the total service in regional state park police service used as a basis for pension credit under this paragraph four and paragraph three of this subdivision e shall not exceed twenty-five years, and

(b) The amount of the additional pension payable pursuant to this paragraph four shall not exceed the amount needed to increase the total amount of the benefits provided under paragraphs one and three of this subdivision e to one-half of the final average salary, plus 5. An additional pension equal to the pension for any creditable service rendered while not employed in regional state park police service as provided under paragraphs three and four of subdivision a of section three hundred seventy-five of this article. This pension shall:

(a) Be payable only if such member has attained age sixty at the time of retirement and has not completed twenty-five years in regional state park police service for which he receives credit under this article, and

(b) Not increase the total allowance to more than he would have received had his total service been rendered in regional state park police service. f. The increased pensions to any member in regional state park police service, as provided by this section, shall be paid from additional contributions made by the state on account of such members. The actuary of the police and fire retirement system shall compute the additional contribution for each member who elects the special benefits provided under this section. Such additional contributions shall be computed on the basis of contributions during the prospective service of such member which will cover the liability of the police and fire retirement system for such extra pensions, and upon approval by the comptroller, the additional contributions shall be certified by the comptroller and shall be included in the annual appropriation to the pension accumulation fund of the police and fire retirement system in the manner provided in section three hundred sixteen of this article. g. In computing the twenty-five years of completed service in regional state park police service full credit shall be given and full allowance shall be made for service of such member in war after world war I as defined in section three hundred two of this article, provided such member at the time of his entrance into the armed forces was in the regional state park police service or a member of the division of state police in the executive department and for service in time of war during world war I and service with the American expeditionary forces subsequent to November eleventh, nineteen hundred eighteen, and prior to June thirtieth, nineteen hundred nineteen, of honorably discharged officers, soldiers, sailors and marines who were actual residents of this state at the time of their entry into the military service of the United States, and the service of members of the national guard in the military service of the United States of America pursuant to the call of the president for Mexican border service. h. Service in the division of the state police in the executive department shall be considered allowable service in regional state park police service, for the purposes of this section, provided that the member pays or has paid the required contributions and provided, further, that in the case of employees entering or re-entering regional state park police service on or after July first, nineteen hundred fifty-four, only credit for service as a member or officer of the state police (including service granted pursuant to subdivision g of this section and credited as state police service) shall be so allowable. i. The provisions of this section shall be controlling notwithstanding any provision of this article to the contrary. j. Notwithstanding any provision of subdivision b, c or i of this section to the contrary, a member who is in the collective negotiating unit designated as the security services unit and established pursuant to article fourteen of the civil service law and who has elected or is required to contribute in accordance with this section may, on or before March thirty-first, nineteen hundred seventy-three, elect to come under the provisions of section three hundred seventy-five-h of this article. Such election shall be duly executed and filed with the comptroller.