Any member of the Teachers’ Retirement System who is now entitled to receive credit for prior service and whose service as a teacher, as defined in Section 16-25-1, was interrupted by service in the armed forces of the United States during World War I shall be eligible to receive prior service credit for such military service; provided, that such member submits proof under such rules and regulations as the Board of Control shall adopt to show:
(1) That he was employed as a teacher prior to April 1, 1917;
(2) That he entered directly into the armed forces of the United States from such teaching service; and
(3) That he returned to teaching service in the public schools of Alabama within one year following an honorable discharge from the armed forces.