Machine shops think of methods using the machines they have, and need to think of how long it takes to set up, then do the machine operation , to do 1, if they have 100 to do they make a fixture for quick setup, you will get a better price when you bring them 100 to do
Since you want to make the profit you need to think of a method using resources you have ---take an old sector, make a hole that a setscrew can hold a cutter, use a drill press to turn it, use a long screw it the sector endplay screw hole for an advance (turn it slow to control cutter feed), make a fixture (wood frame, wrap housing in plastic wrap -set in bondo --can make reusable form fitted fixture. --no drillpress--use pitman arm, turn by hand until profit can buy tools
I used a fat o-ring, with a washer like Brattons sells, the recess can be at an angle, the o-ring doesn't have to be square to the shaft, with a positive seal it needs to be square to the shaft.
The 2 tooth is easy to set up in a bridgeport, I have been playing with grinding some original sectors with little wear on the teeth a few thou smaller and custom making bushings to fit.