(a) Be payable only if such member has attained age sixty at the time of retirement and has not completed twenty-five years of service as a member of the regional state park police 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 as a member of the regional state park police. For the purpose only of determining the amount of the pension provided herein, the annuity shall be computed as it would be:

(aa) if not reduced by the actuarial equivalent of any outstanding loan, and

(bb) if not increased by the actuarial equivalent of any additional contributions, and

(cc) if not reduced by reason of the member's election to decrease his annuity contributions to the retirement systems in order to apply the amount of such reduction in payment of his contributions for old-age and survivors insurance coverage. e. The increased pensions to members of the regional state park police, as provided by this section, shall be paid from additional contributions made by the state on account of such members. The actuary of the retirement system shall compute the additional contribution of each member who elects to receive 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 retirement system for such extra pensions. Upon approval by the comptroller, such additional contributions shall be certified by him to the commissioner of conservation. The amount thereof shall be included in the annual appropriation of the state for the conservation department. Such amount shall be paid on the warrant of the comptroller to the pension accumulation fund of the retirement system. f. In computing the twenty-five years of completed service of a member of the regional state park police, full credit shall be given and full allowance shall be made for service of such member in time of war 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, marines and army nurses, who were actual residents of the 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 or Mexican border service. g. 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 shall be so allowable. h. The provisions of this section shall be controlling notwithstanding any provision in this article to the contrary. i. Notwithstanding any provision of subdivision a, b or h 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.