Looking at the reverse of this cent it looks a small piece was peeled off maybe lamination error? Or pmd?. the 1951S wheat cent looks like upside down S or is it just me.
Looks like the first cent had been glued to a board, then popped off. I also don't see anything abnormal about the mint mark on the 51-S.
The mint mark looks oriented correctly. Flat Serif on the top and Bulb on the bottom. The Shield Cent looks like gunk not to mention the fact that these are copper plated so lamination is out of the question.
