Even though you got to a year in a convoluted way
, I think you are correct. The earliest the set can be is 1957 based on Kubek (his first year was 1957). I don't think it's later because I have a set that I believe is from 1958 and a set I know is from 1959 which are about 6" by 8-1/2" and have 16 photos in each set. I also have a set that I think is from 1956 that has Collins and Martin instead of Kubek and Stengel. It's possible that mine is an earlier edition of 1957 since that was Collins' last year with the Yankees and Martin was traded away in June of 1957.
I'd put the value anywhere between $100 and $150.
If you're interested in selling, let me know. I'd be interested in buying it.