Has anyone ever seen a mintmark like this 1970-S Lincoln Memorial cent? Without a loop I at first thought it might be a RPM, but upon closer inspection it looks like it was struck on a cud?
Just a typical 70's low grade mintmark. IMO, the 70's were the worst years when it came to mintmarks. Looks like it might have taken a hit along with being a poor design. Also not cud, that would be a die break from the rim inward.
You might try www.doubleddie.com and see if you can match it up, hey I give you credit you new it was a large date. Lol Dave
Correction.. a CUD is a Die Break that involves the edge of a coin. This is a CUD - Mint Marks that are filled in would be called Die Chips. It is also a Die Break but on small not involving the edge.