Up for sale here is this set of 2 new black Bakelite pointer knobs. These look vintage but are newer. They measure about 1.3125" in diameter.  The holes are a hair smaller than 1/4", so these will work perfectly on ribbed 1/4" shafts and 6mm shafts.  You can drill them a little wider if you want them to fit a 1/4" round shaft or a 1/4" D shaft.  These lock on with flat-head set screws (included). These would look amazing on your guitar amp. Please see my pictures for details.

US shipping and handling is $5, and international is $18, 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. If you have any questions, please ask.

I have more knobs and other vintage electronics listed--feel free to take a look!