Ouch! I've taken loads of photos and taken notes so I should be able to get it back together properly.
I finally got all the rust off the chassis then applied some Rustoleum "Rusty Metal Primer". I'll go a few rounds of sanding and primer to fill in the pits.
The cadmium plating was fine in the unpainted areas.
I also popped out the two rivets holding on the IF coil shields so I can replace the rotting grid cap lead. It makes it easier to paint around too.