Your 1956 looks like it could be an FS-401 obverse die clash mark. Also, the 1958 reverse looks cleaned at first glance, but I’d say the parallel lines in fields around & below the bell are probably die scratches.
I have always thought that my 56 looked like Franklin was crying his eyes out-- probably because he learned that my little sister had just been born.
Really cool set. Wish I had done it like this. I wanted every date and mintmark and it was just too much to finish. I gave up and left a lot of holes of even a date set. I love the matching look you built. That's not easy.
Thanks, I enjoyed putting it together. I knew from the start that every date/MM was impossible. I did set a goal of acquiring at least one example of every MM per series--just not every date (or for that matter, every type within a series.)