Re: Fender bassman 135 fix...
I second the Major's assessments. 470 ohm 2 watt resistors are typically what most Fenders used stock. You don't want to overrate them too much. The fact that one got taken out when the valve shorted is a good thing as once the screen resistor goes it basically pushes that valve into cutoff and turns it off. As such, the screen resistor acted as a fuse. Overrating it will make it harder to blow in the event of a catastrophic failure where it can cause much more damage, such as taking out an OT or possibly even a PT.
Two 100 ohm resistors off the heater winding to create a false center tap is also common practice as well.
And 100uFs are fine for the bias filters as well.