It could also be the ignition switch... it's probably 40 years old too.....
Bet the wiring is original also. Maybe he should rewire it?
Come on.... at least try and help the guy. Don't just guess bad parts. That's not helpful at all.
You didn't offend me. Not at all..... but I get irritated when people just guess at problems because:
One time I had a similar issue and "XYZ" was the culprit, so that must be the case with your machine. Or
"Try replacing these parts in this order." Anyone can guess.... but most people can guess just as well on their own.
What does purchasing from all the sponsors have anything to do with it? We don't get commission from them on sales on here.