That is an interesting piece indeed. Seems 1955 was a good year for these cracked dies in the head area. Could you show a full slab photo?
There is a red thread in his head as @ldhair said. @alurid - I didn't know this was common. It would follow that the Mint took notice and lowered striking pressure to extend the life of the dies. Which caused the weak mushy strike that I mistook for an obstructed strike. I like it. Thank you.
I don't know if 1955 had more Error coins the any other year, or it just seems that way because 1955 coins where seached through more because of the "1955 Double Die" and more "Minor Errors" were found. I have 3 "55's" with Minor Errors.