Here is a chassis layout of my Twin Reverb. I suspect that it might have been modified a little bit before I owned it, but I think it's mostly per the factory schematic. I am 98% sure that the 1 ohm resistors on the cathodes of the power tubes were added after the amp was made to make biasing the amp easier.

The first link is an as-built of my amp. The second one shows what has to be done to convert it to blackface specs. My approach keeps the hum balance pot and adds a bias control pot. The master volume to be removed is shown dashed in orange. The stuff that needs to be replaced is shown in magenta. Optional items are shown in a light blue. You can isolate them using the layer control dialogue box on the left had side of the PDF.

100 Watt Silverface Chassis Layout (with master volume)

100 Watt Silverface Chassis Layout (blackfaced, no master volume)