Very nice coins. I have several of these, also from the 50's and a couple of 1960. They are low-end Errors, and definitly keepers. The 1951-S looks like a Lamination Error. Which is better than Die Cracks, IMO.
NICE! Keep putting them all together when you find them and soon you’ll have more crack heads than you can find at a Seattle Bumbershoot celebration! Keep hunting! Reed.