i have thought I have had a 1979D - RPM more than once. I have posted one here and was told it was
Die Deterioration. I have since seen other posts and they have been told pretty much the same thing. here is another - hopefull. I'm not sure if this is any different but the mint mark has a very pronounced notch in the lower serif. there are only three RPM's listed on coppercoins. the 001 does not show photos. could this be one. thanks.
