You might want to read this before it's moved and you miss out on the information.
Updated article as of 10/18/17:
David - what was that site you posted back in June where you got your metal knobs from?
Thanks!
Here it is:
BTW If you want these knobs or similar high quality knobs you can visit Digi-key. No, I don't work for them. The specs. on the pot shaft are 6mm or at least my 6mm knobs fit perfectly. The 1/4" size shaft-for-knob might also work using the set screw. I operate my M8 under a CP1 and at night in my studio which can be rather dim or dark. The original knobs in black are hard to see, too wide at the base also whereas these gloss finish knobs reflect the LED light and really illuminate. They have a practical application other than just being superior in quality.
Another observation it that the unlit area buttons are gray which blend perfectly with these knobs.