I finally was able to sort all of those copper cents by decades and do a such for 71s, 72s and a few mintmarks that stood out. Pics will follow tomorrow. 1 - 1971p 1do-001 1 - 1971p 1do-003 2 - 1972p 1do-003 1 - 1972p 1do-008 1 - 1960d 1mm- ? havent searched it yet but it looks like a -027 1 - 1971d 1mm-009 ? - 1979d 1mm-003 (I stop counting after 5) 4 - 1957d 1mm-031 (BU)
Clutchy, I have a hunch that the RPMs you are seeing on the 1979 are just the broken MM punch that give the illusion of a widely-split lower serif. They are VERY common.
