for sale here is this NOS vintage 1963 Mallory 100 ohm potentiometer with power snap switch. I do not know if this is audio taper or not, sorry. This is labeled "685-230 235316" on the potentiometer side, and "PR Mallory 6A 125 VAC 2A 125 VDC Made in USA" on the power switch. Basically this is a combination volume & power switch, so when you turn it initially the power switch turns on, and then the volume control goes up. The "235316" code means that this was made by Mallory (235) the 16th week of 1963.
This has a short ribbed split 1/4" shaft, so any standard 1/4" round knob that locks on with a set screw will work, as will any ribbed shaft knob. This is guaranteed to work great for you, though it may need some Deoxit. This is a pretty rare potentiometer. Please see my pictures for details.
US shipping and handling is $4, and international is $14, 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!