2nd warning:

I remember the brouhaha here about making a patented center marking
device for square blanks, so _DO NOT_ [repeat, DON"T] sell these
knockoffs.)

Since I'm the guy offering Longworth-style chuck plates right now, is
that what prompted this warning, or is this specifically in regard to
center-marking guages? I don't have any interest in being blindsided
by a lawyer or three when a simple e-mail or phone call could probably
clear it up!

Of course, anyone who knows of or can make a solid claim of patent
infringement should let me know, and I'll refund the deposits I have
received for the plates and forget making them- but it seems like fair
use to me, as the plans are all over the internet and published in
magazines!