About twelve years ago, I bought the Wax Machine System from Frei &
Borel. This was a collection of tools that allowed you to make
different kind of wax ring models (eternity, faceted, domed bands,
etc., using standard wax ring tube stock. At that time, you could opt
to buy only the “Basic Wax Machine Unit”. It was a coring devise
that allowed you to cut perfectly straight ring sizes in standard wax
ring tubes by adjusting a cutting blade. Once you adjusted the blade
to the proper size (NOTE: If aiming for a large size, you would cut
in stages, perhaps two size increments.), you would shove the the
registration rod into the wax tube and crank the gadget clockwise.
The cutting blade would core out wax to the desired size and you
controlled the width of the ring by how much tube you cored out.
Once you’ve cored out the size and width you want, you put your wax
tube into a miter box and saw off your ring blank. Needless to say,
this gadget is very handy as it doesn’t cut tapered, off-round, or
choppy ring holes. While I haven’t seen it in catalogs for years, you
might contact Frei & Borel and see if they can track one down for
you. If my memory serves me correctly, the price was around $150
back in the 80’s.