I'm not sure how you'd get it all done on a lathe, as the inside relief for the moon clip comes in further than the extractor star. I've only seen it done on milling machine.
On my guns, the numbers marked on the cylinder don't correspond to a serial number, but are just to know what hole you're shooting out of every time. I've never bothered to see if some holes shoot more accurately than others, but I guess if you were really detailed on those issues, it'd make the job easier to track.
https://www.youtube.com/watch?v=WVfHKkAAE50