The screen resitor was burnt, being it's 1/2 watt this is not unusual. It was also melting the anode wire on the output transformer.
You can see how the paint is discolored in the middle. I relaced it with a 3.3k 3 watt wirewound:
Took out the old filter cap:
Next replaced the missing 150 ohm cathode bias resistor with a 5 watter:
Last thing done was to lift the ground on one end and install 2 100 ohm resitors as a hum balance between the heaters and ground. A trick I learned on these from a really thankfully picky and pushy customer. Amp runs quiet now and PACKS A PUNCH!
Play loud, play well! Jef