Back in the day, I was involved in making recorders (musical instruments). This involved making "windways" in the "headjoints". The consensus of makers was that the windway was curved to match the bore of the instrument. I adapted a microtome (tool for cutting very thin slices of frozen tissue) to become a mini shaper. It is a very well made tool that weighs 47 lbs. and has a 2 1/2" stroke. The large wheel at the bottom adjusts the depth of cut 0.025" for a full revolution, so very fine cuts could be made. I expect many other applications are possible. Willing to be flexible on price to a keener.