Guitar Amp Repair Question(Soldano Hot Rod 50)

I have an early nineties Soldano Hot Rod 50 amp and need to replace a stripped pot in the preamp section.(First knob actually.)
I am clueless as to what type of pot to buy...Can you help?

The pot will have a value (e.g. '100k log') marked on it somewhere. So the replacement will need to have a similar value. You may not be able to get one the same physical size.....pots seem to have shrunk over the years
I'm not familiar with that amp. Is the pot for volume control or.....? Single or dual? With/without switch?