I have a similar fellow who does all the smaller pieces for the jet engine tools.

Has been in business, working with his own two hands, for 35 years.

Can typically work to .0005 on a lathe. Then, of course, it is sent out to a proper grinding shop for finished size, and runout requirements.

He's made some beautiful parts over the years............but.........he's French Canadian...........so don't even attempt to tell him anything.............and............he's never wrong.