Also
Machine Doubling on the right side of the date devices. On a doubled die the devices would be enlarged, not reduced.
Here is a 1988 DDO-005

Note the width of the devices. Especially on the '88'. Note the right side of the devices are wider than the left side of the devices on each '8'? That is what to look for on the 80's DDOs on the zincolns.
1989 WDDO's

Again note, the devices are not reduced, because if there were it would be
Machine Doubling. But note on the '8' again how the one side of the '8' is wider than the other side.
Edited by coop
08/09/2019 9:38 pm