09-08-2017, 01:18 PM
"Hot chassis" or, I'd rather call them AC/DC radios, typically AA5 or sometimes 4 or 6-tube jobs, were made from 30-s all the way into 50-s and so used different wires. I treat them on the individual basis, and not as a group. If you see the wiring is crumbling, then rewire; if not - leave it be.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.