Voltage checks showed no voltage at the oscillator. Found R10 open. It is a 10k wire wound resistor. How can I determine what wattage the replacement needs to be? The parts list shows 10K but doesn't list wattage.
Most likely a 1 watt will be OK but a 2 watt for sure will be excellent. R-10 is only feeding the plate and screen grid of the 6J7
Osc tube. Since resistor is open do an ohm meter test from the plate to chassis and Screen Grid to chassis. If done before replacing that R-10 resistor it should read infinity or close to it. If Low Ohms then look for some short. Most likely it is OK and some leaky bypass cap is what caused R-10 to open up.
PS. Check R5 and R6 while your in there to be sure they are OK.