77 D IMO is environmental damage not a mint error the 66 IMO is DDD ( die deterioration doubling). JMO Dave
I noticed on the 66 when look at a different angle, I notice it was thicker on one side. Can anyone explain?
Btw, thank you guys for taking your time and reviewing my question. I am of course new to coin collecting and want to be a little more knowledgeable about this subject so I can pass it on to my step son and daughter.