Both controls were frozen up more solid than any I've encountered before. Eventually, with the aid of some penetrating oil, rust dissolver and heat, I got the band switch working
The volume control/power switch wasn't quite so easy. I found evidence someone had pried it open and tinkered with it in the past and was ready to write it off as a lost cause. I kept at it though and finally got it working quite well, but in the process ruined the metal tension ring.
By the tensioning ring do you mean the "C" clip that fits in a groove on the control's shaft? I would try removing one from a scrapped control and see if that fits, you need a sharp flat bladed screwdriver to push them off the shaft, sometimes you need to pry the ends open with a jewelers screwdriver or something first.
Regards
Arran
I suspect your local hardware store will have a series of different sizes of these "C" type retainer rings. One might be close enough to do the job if you don't have one.
The trouble is that the usual hardware store "C" clips are completely different from the ones used on potentiometer shafts, the ones they use on controls go almost 360 degrees around and are pinched closed. The only thing I can think of is maybe cutting a slot in a thin washer and prying it open, and then pinching it closed again over the shaft.
Regards
Arran
I can't remember what they are made out of but it may be aluminum. In any even at least you found a replacement ring, it's always nice to be able to salvage an original pot when you can.
Regards
Arran
I also never understood painting chassis. Unless that was how it was originally, to me the chassis is metal, to be contacted every time you need a Ground. Best left unpainted.
Looks nice.
As long as the paint is conductive and is not separated from the metal by non-conductive primer, I guess it's OK.
I am (actually currently) dealing with the certification to EMI/Safety stds of a devicde that had every plate in its box anodized...what a PITB. We had to scrape the anodizing to make the box conduct. It was radiating like heck. Chassis should be conduictive.