[simplex1040]

Nice radio

I believe toggle switch is original on that model. For rubber coated wire it is best to replace all of it, changing one wire at a time so you won't get confused.
as far as the transformer leads I have put shrink tube as sleeves on the wire and just carefully shoved it into the bell housing to fix crumbly wire. rattle tube i would look for replacement, dark burn't spot on rectifier is "getter flash" Where they burned off any excess oxygen in the tube during manufacturing process, don't worry about that.