[upcountry miss]

Time for me to bow out of this controversy. Although most of what you say is undoubtedly true, I have no recollection of any year stamp coming in individual units, so my take on it is that two digits had to be cut off and why would anyone do this, and then position the remaining two digits to the right, instead of centering them?

[muawiyah]

Ref the exhibits in the Postal Operations Manual. NOT ALL DATES or DATE ELEMENTS are centered.

Another guy to check with on these round dates is named Arthur Porwick. I think he worked on that project a bit. Hexter didn't stick around after the mess in Charleston PO.

Rubber/Plastic self-inking inserts were all the rage throughout industry at roughly that time (1980). Still are!