I bought this old jukebox amp because it looked like a relatively cheap way to get a relatively powerful tube amp: 20 watts per channel. Upon receiving the package, I promptly stuck the amp on a shelf to wait until I had the time to give it the once over. After careful inspection, I discovered that most of the wiring, including the leads from the transformers, had disintegrating insulation. Moreover, the leads for the power transformer and one of the output transformers not only had disintegrating insulation but also corroded, brittle copper wire. There was plenty of rust to contend with as well. This video shows the restoration of the amp from a rusty, crusty, hunk of steel to an attractive amp with lovely sound!
Correction: The bias supply is connected, via 250k resistors, to the grids of the output tubes, not the cathodes. Hence the term "grid biased." Duh.