GE 7-4333 with Blown Volume Pot

[maduko]

Knew something was amiss when the volume knob turned freely. Turns out it's destroyed inside.

"Blowed up, sir!"

Is there are source for finding such parts? Or is a donor unit the best option?

[NoTime]

I don't know about that specific one, but if you can read the markings off of it, eBay and salvage parts houses are full of things like that.
I'd also recommend replacing all the electrolytic capacitors while you're in there. One at a time if you can.