A long shot, but did you check out Donald A. Dixon in Arlington, TX ? Shows approx. age 66, would have made him 25 or so in '72 - currently about 150 miles from San Angelo, near Dallas. If he was originally from Texas, he probably never left the state after the service - those Texas Longhorns are mighty proud of Texas, kinda like us Volunteers are of Tennessee. Worth a look -
Regards,
Steve