Ken,
I've got several of Joe Woods coning tools. I'm thinking it would be really easy to adapt these to do the same thing.
Drill a cross hole, add a set screw and viola!!
By the way, my dear old uncle had a saying about that...... "Sometimes even a blind pig finds an acorn" (I just got lucky)
It will be a new direction from the "Heinie Muzzle", ala Don Getz.