for sale here is this vintage CTS 100k ohm linear potentiometer. This is circa 1944 and is Made in USA. This came off a piece of tube equipment from 1944. This has a short 1/4" round shaft, so any standard 1/4" knob should fit. This is guaranteed to work great for you, though it may need some Deoxit. I tested it and it tests right around 100k ohms. This has light to moderate wear and some dust/grime from age, and the terminals have a little vintage solder and wire bits on them. This is a pretty rare potentiometer and would be great on your guitar or amp. Please see my pictures for details.
US shipping and handling is $4, and international is $16, no matter what quantity you buy. All my small parts are set up for combined shipping, so just use the "add to cart" feature and then check out all at once, and it will combine shipping. I accept Paypal. If you have any questions, please ask.
I have a number of other vintage parts, collectibles, Magic cards, and vintage electronics listed--feel free to take a look!