[MrFixr55]

Gotta go back to work. Are the Hor Output and Damper on the PCB? Looking at the schematic, one heater connection has the "X"X the other is chassis ground. If these tubes are on the PCB, really smells like the cold solder joint on the chassis post issue. Solder a wire to the appropriate socket connection on both tubes and find a good tang to solder it to nearby on the chassis. It will strengthen the connection. It is likely that these 2 tubes draw the most heater current of all the tubes in the set. I wouldn't be surprised if this is the issue that put the set out to pasture in the first place.