[Ron Ramirez]

Also I found out that someone had changed the 6A8 tube and socket for a 6A7 tube and socket.

Could be a wartime repair, as parts were short and repairmen had to do the best they could to "Keep 'em Flying" with whatever they had on hand. A 6A7 is electrically identical to a 6A8 but of course the pinouts are different with different basing, too.

That should be a nice project for you. Don't forget the rubber-covered wiring including the wire leads from the power transformer. Good luck!