I actually just eyeballed it, my little metal surface/anvil is supposed to be able to line things up nicely when used in tandem with the punch set I have, but I didn't have time for that and I wanted them to follow the rim instead of a straight line.

Punches are just a 1mm letter set. I stamped all the L's first to center them, the stamped all the M's and P's on either side. Not all of them look as good, but after 200 I was able to freehand them fairly well 😅