I would pay you good money for one of those knobs, especially if you could match the paint of the handles. Makes it much easier to find in a dark bag. Seriously, hit me up in a PM if that's a possibility.
Ha! That would be the first good money I'll have seen in a long while in that case
Seriously though, I'll see what I've got and let you know ...
Maybe there's a market for 'em, like the red anodized shutter buttons some Leica owners just have to have
...erk, did someone say 'CNC'd in China'? There goes my business model, LOL
(PS--Yes, the original knob just pulls off--if you can grab hold of the stupid convex shape(!) The shaft has a flat, the rotational position of which is non-critical, so many knobs made for either 6mm flatted shaft, or 6mm dia. with a set screw, or even just a firm push-fit, will work. Just remember not to set the knob hard against the front panel, as some small amount of clearance is needed for it to also act as a push-button.)
Dave