Hi
When you say “striped” what do you mean?
I have the same setup you do and the knobs are held on by a set screw in the side of the knob.
If you have lost a knob you will find a replacement in the first link I posited.
If you have striped the threaded hole in the knob you can find the next sizes larger set screw in the second link I posted.
If you need a tap to thread a little larger hole they are in the last link I posted.
Between the three links you will be able to replace or repair your knobs.
Tthis is a picture of the stem the knob goes on. You can see the notch the set screw goes into to keep it from spinning without turning the valve.
This is the knob.
This is the bottom of the knob. You can see the hole is round.
This is the set screw I am talking about.
Phil