Note all the areas you are looking at on on the outside edges of the devices, which is where you find
Machine Doubling. RPM's last year were 1989. SO post 1990, doubling on the mintmark area would be
DDO's. But again this is just MD. On A
DDO, the devices will be enlarged:
_AAA.jpg)
_AAB.jpg)
Note the mintmark area and the date are showing the
DDO.