Up for sale here is this NOS NIB vintage IRC Q13-133X potentiometer. This is a 500k ohm audio taper potentiometer. It tests around 523k ohms on my multimeter. I believe this is dated 1950. This has a nice long 1/4" half shaft, but you can cut that down if you want to use this on a guitar. Any 1/4" knob with a set screw should work on this, and I think most "D" shaft knobs will as well. This is guaranteed to work great for you, though it may need some Deoxit. Please see my pictures for details.

US shipping and handling is $5, and international is $18, no matter what quantity you buy. All of my small parts are set up for combined shipping--just use the "add to cart" feature and then check out at once, and the shipping will be automatically discounted.

I have a number of other vintage parts, collectibles, Magic cards, and vintage electronics listed--feel free to take a look!