Hello I have a friends amp here. His master volume potentiometer is shot. Some dude sprayed something in there to clean it and no it just spins freely.

I can solder, and I know what I'm doing but the thing is I can't find a replacement pot! I believe it's a 11mm B10K vertical pot, but I can't find that value anywhere. All 9 pots are labeled B10K.

Any help?? Who to call??

Thanks!!