Quote Originally Posted by morsa View Post
.... There is also the option, easily available today, to make them through 3-D printing.
These are some examples of 3D printed knobs:

https://www.thingiverse.com/thing:904784
https://www.thingiverse.com/thing:1051825
https://www.thingiverse.com/thing:2451628
https://www.thingiverse.com/thing:2352177
https://www.thingiverse.com/thing:2121898