Raimey;
Do you take the .626 & .637 as bore dias from a later proof? Certainly seems inconsistent with an earlier proof @ 16.3 (.642")& 16.4 (.646"). I am in agreement with your interprtation though, just doesn't look right that it could have been proofed at a later date & the bores be smaller. Do you have any ideas as to what occured here?

Miller/TN
I Didn't Say Everything I Said, Yogi Berra