Excellent remarks!! Made all the difference.
Suggestion by coreplayer2 taught me how to edit Xprogs instead of disabling it and it works as advertised. So now Xprogs is in play and the wbar buttons I wanted to remove are gone.
With Xprogs not disabled I went back to check on Misalf's original suggestion of using fluxbox and custom menu file. This has a similar effect to the approach Rich suggested with flwm. Most of the menu items are removed but three are left in, one of them is Exit which, as said, I must remove too.
And last, sending me back to the hall of shame, curaga's remark about comment in JWM's .jwmrc. I removed the section that is relating to the menu from .jwmrc and sure enough, no menu!!! That statement was staring me in the face every time I parsed this file for possible clues and I never
saw it until curaga pointed it out.
Double gain this time: Learned how to work with Xprogs and finally, figured out how to disable the click menu.
Thank you all for your excellent input and good help!!