I remember years ago my young fella broke a bakalite spur gear in our valve refacing machine and we were in a huge hurry to get it up and running so I got a old tap that had the same pitch as the gear and ground 3 of the flutes off and used it in our bridgeport turret mill to cut the teeth on a alluminium blank we machined,that machine is still running perfect at least 6 years later.I guess if its not a accurate part theres lots of ways to fix. it