I'm gonna say MD/deterioration,I dont see any real separation on there,flat and shelflike,I'm no expert,just my opinion
It looks like it was caused by a deteriorated die to me, but I'm not as smart as *i2i*. Why don't you ask him? Chris
This is a DD,notice the same height on all devices,not flat. Clear separation on the letters,split serephs. This is a 1965
that looks like deterioration,it shouldnt show on all sides on the device,but in one direction i believe