I wasn't able to devote much time this weekend to the chassis, although I spent a little time on the grille and cabinet (just to get it out of the living room!). I stripped the cabinet down to bare metal using paint remover and a wire brush wheel on my drill. There was a bit more rust that I realized, so I dabbed on some rust remover, then more wire brush action. The grille came out pretty good, using the blue/silver/black metalized cloth (for some Fender amp) I bought from Mojo. Since I had the original cloth to use as a guide, cutting the replacement was simple.
Before:
After:
I still have to clean up the corners...
I used fabric from a white linen napkin to cover the speaker hole prior to mounting the grill cloth and painted the masonite board a matte finish white. This made the hole invisible and the white brings out the silver threads very well.