Any prior class member shall be entitled to benefits under the retirement system determined in accordance with the superseded system of which such member shall have been a member, as in effect on July 1, 1972, with the following modifications:
(1) The rate of benefits applicable to the “average final compensation” of Class B members of the Tennessee teachers' retirement system and to the “average compensation” of Class B members of the Tennessee state retirement system shall be increased from one and three-fourths percent (1 ¾%) to one and seven-eighths percent (1 7/8%);
(2) Sections 8-34-602(e), 8-34-712 and this section shall apply to present members of Group 3 as well as members coming into Group 3 prior to September 1, 1974.