The Stovebolt Site Forums The Shop Area The Electrical Bay The Radio Bench A few questions about original radio wiring.

That is correct for ground
The main body of the radio is the intended return

adding a dedicated wire from the inside chassis on transformer side would not hurt.

There should also be a dedicated dial lamp wire to connect to the back of the light switch
The dial lamp will dim with the instrument lights
The dial lamp wire is also switched inside the radio so when the radio is off the dial lamp is off as well
-s