Yes, I agree. The 1955 appears to have a die crack. The 1956 I'd call a die chip on the wheat stalk. These are actually quite common in that location. I would not call it a cud - a cud specifically refers to a die break at the rim.
The 50's are notorious for overworked dies. Lots of chips, cracks, breaks and washout. You could be labeling for days if you have a lot of 50's LWCs to look through.
Not a cud. You do have a die crack and a die chip, both are common. This is a Cud, a large one but it's a Cud.