The paper notes a (to me) amazing thing. The object of the researchers' Bayesian analysis is the number of holes likely to have been made in a metal ring, of which only a fragment remains. They think either 354 or 355 holes, on a 77.1mm radius.

The amazing thing is that the holes were placed with an average radial variation of only 28µm. This is about 0.001 inches. 2000 years ago. Our ancestors had some serious skills.