(a) The provisions of this or any other law to the contrary notwithstanding, the head of any state department or agency who is an elected constitutional officer and who was previously ineligible by law for membership in the retirement system may, at any time on or before March 31, 1965, elect to become a member of the retirement system by notifying the director of the Employees' Retirement System of Georgia.

(b) Upon the effective date of his membership, he shall begin making regular employee contributions under this chapter and shall be entitled to all the retirement allowances and credits under it in the same manner as if he had become a member of the retirement system on January 1, 1950, which credits shall include credit for prior service and any service performed by him as an employee after that date.

(c) All employer contributions which would have been reported for such a person between January 1, 1950, and April 1, 1964, shall be paid by the employer into the pension accumulation fund in such manner and over such period of time as shall be agreed upon between the board of trustees and the employer.

(d) Eligibility for survivors benefits for any such person shall be determined on the same basis as that applicable to all other members who were in state employment on or after January 1, 1953, and benefit amounts shall be based upon the age of such person on the effective date of his membership with the retirement system.