For purposes of this Code section, the terms "Justice Emeritus of the Supreme Court" and "Justice Emeritus" mean both Chief Justice Emeritus and Associate Justice Emeritus, and the term "Justice" means both Chief Justice of the Supreme Court and Associate Justice of the Supreme Court. The provisions of this or any other law to the contrary notwithstanding, any person who becomes a Justice of the Supreme Court after April 1, 1964, shall be a member of the retirement system and shall not be eligible for appointment as Justice Emeritus of the Supreme Court. The prohibition against appointment as Justice Emeritus shall not apply to any person holding either the office of Justice of the Supreme Court or Judge of the Court of Appeals on April 1, 1964. Any person serving as Justice of the Supreme Court on that date must notify the director of the Employees' Retirement System of Georgia on or before March 31, 1965, if he desires to become a member of the retirement system and shall otherwise be ineligible for membership. No Justice of the Supreme Court shall be allowed to rescind notification nor shall he be allowed to give notification after March 31, 1965. Any Justice of the Supreme Court who becomes a member of the retirement system shall, upon the effective date of his membership, begin making regular employee contributions under this chapter and shall be entitled to all the retirement allowances and credits under this chapter 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 services performed by him as an employee subsequent to that date. All employer contributions which would have been reported for the Justices of the Supreme Court 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. Eligibility for survivors benefits under Code Section 47-2-128 for a present Justice of the Supreme Court 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 the Justice on the effective date of his membership. Eligibility for survivors benefits for any person who enters on duty as a Justice after April 1, 1964, shall be determined in the same manner as for any other new member of the retirement system.