Buy a solid knob, then drill and tap as req'd.


If the threading on the knob (either bolt or nut) is a common size
(i.e. 1/4-20 or 5/16-18) you could probably find a replacement in the
"jig hardware" sections of Lee Valley, Rockler, etc.
http://www.leevalley.com/wood/page.a...,43455&p=52800
Good luck,
Andy