Group, I plan to mount my plasma cutter in a fixture in such a way
that I can feed 4130 tubing under it to cut saddles.  The tubing
would rest on a receiver which would allow me to move it in and out
and also rotate it.  I don't plan to follow templates, just silver
pencil marks  the same as I do now when grinding the saddles. The
advantage would be that the cut would be perpendicular to the wall
(grinding and all rotating tools make feathered edges), it would be
very fast and much cleaner than grinding.  Does anybody see any
reason why this would not work?    Jerry

Sounds like a great idea Jerry. You could make paper templates using 3D and
transfer the curves to the tubing with silver pencil.