Threads appear to be right hand...not left hand on the post on my pump that does not have a knob.
And
If they were left handed, the knob spins freely clockwise on the shaft...so turning clockwise while holding the shaft is a mute point.

Any chance this knob is two parts and the outer part would screw off and expose a nut on the shaft hilding the second part on?

Can't believe nobody has done this before

I just dont want to wreck it or marr up the brass

Thanks!