I have two quarter proofs with a different reeding design. The 1969s weighs 5.7 and is the one showing a narrower top surface of the reeding. (Pic on the left) The 1968s weighs 5.4 with a larger to surface of the reeding. Any ideas?
Possibly new and worn collars. Could also be a difference in the collars between the two years. As Kanga said not a lot of attention has been paid to the collars and there could be differences in the collar from one year to the next.