I think I still have some black Bomar threaded studs & knobs from replacing them on my previous boat.
If anyone is interested in them - PM me and let me know how many you need and mailing address -
I'll check the spare parts bin and let you know!
Also - If the problem is the knob threads being stripped - You can drill them out and epoxy in a threaded brass insert
Threaded Brass Insert - Plastic
Threaded Brass Insert - Wood