Reported by Tomxp411 on the community forum via private message:
Also, there's a good source for key stickers online. Amazon has both black and white key stickers, and they're a vinyl-like product that is pretty durable and can even be removed and re-applied. I've got two sets now; one is on my Coolermaster keybard, and the other is just sitting under my monitor for visual reference (I just look at that, rather than my hands.)
Here's one example: www.amazon.com/COMMODORE-NON-TRANSPARENT-KEYBOARD-STICKERS-BACKGROUND/dp/B000ZXOUB2/ref=sr_1_1?ie=UTF8&qid=1524815680&sr=8-1&keywords=commodore+64+stickers
4Keyboards Commodore keyboard stickers page:
Those examples are of aesthetic value primarily, but could fit other purpose.
Ready made found here:
Custom stickers:
This site is known of unixstickers, made for keyboards and various cases:
Retrobiker from the community forum shared a set of keyboard stickers he made for his keyboard, showing all the special keys (run/stop, restore, clr/home, commodore logo, etc) and also the petscii graphic characters.
But the links don't seem to work anymore so here they are again:
The stickers are available here:
Here's a photo of how he placed them on his keyboard:
Here are the related forum threads: