(a) Since he last became a member, and

(b) Prior to the completion of twenty-five years of total service in the division, 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 such department prior to April sixteenth, nineteen hundred thirty-eight. 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 sixteenth, nineteen hundred thirty-eight, shall be limited so that the total service in such division 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 an employee of the division 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 of service in the division 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 the division. f. The increased pensions to members of the division, 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 of 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. Upon approval by the comptroller, such additional contributions shall be certified by him or her to the superintendent of state police. The amount thereof shall be included in the annual appropriation of the state for state police. Such amount shall be paid on the warrant of the comptroller to the pension accumulation fund of the retirement system. g. In computing the twenty-five years of completed service of a member in the division, 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 for Mexican border service. h. The provisions of this section shall be controlling notwithstanding any provision in this chapter to the contrary. i. Notwithstanding any provisions of subdivision b of this section to the contrary, an employee who is required to contribute in accordance with this section, but is not a member of the state police, may, on or before March thirty-first, nineteen hundred seventy-three, elect to come under the provisions of section seventy-five-h of this chapter. Such election shall be duly executed and filed with the comptroller.