do you mean, talking about bad plate resistors, something like broken resistor easily replaceable with some DIY? Or something more serious?in all of my history i have never seen a volume pot die unless seriously abused.
what you may think is a bad pot could actually be bad plate resistors, way more common on 06t amplifiers.
the dual shaft pots are very hard to source.
I’m searching for picture about that to try to have a more precise idea… without success