Replacement knob for Tobias

[wysiwyg248]

I own a Tobias 6-String, a labor of love as Bass Guitar called them once. The bass is missing the top cap of one of the plastic/rubber knobs. I wonder if anyone here can assist me finding a replacement part.
I already contacted Gibson repair shop unsussessfully and also Mike Tobias, he didn't reply yet.

Any assistance with this is appreciated.
Thank you and peace out.

[saxofunk]

Sounds like it's time for custom wood knobs.
Or, check out mouser.com or tubesandmore.com, they may have the right replacement knobs.