Ala. Code § 36-27-43
Any person who is presently a regular employee of the State of Alabama and is covered or eligible to be covered under the state Employees' Retirement System and who, prior to such regular employment was employed as a fully budgeted school bus driver (not a student), mechanic or maintenance worker by any county or city board of education or the governing board of any public school in Alabama regardless of the source from which and the manner in which his salary was paid, shall be entitled to receive credit for all service in such capacity rendered by him prior to October 1, 1971; provided, that such person shall pay into the Employees' Retirement System, within six months from October 1, 1975, a sum equal to the total contributions which he would have made as a member during the period of such employment from October 1, 1945, to October 1, 1971.
Ala. Code § 36-27-43 (1975)