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runscottThey describe the differences between Dags, tintypes, ambrotypes, etc., various plate sizes, and also the processes used to create the Old Judge and other baseball cards that we are discussing here.
Very good reading and I think a necessity for anyone who has your interests, especially since you are interested in baseball and some of his books relate the photographic processes to that subject.
It might also give you a better idea, not just of the technical possibility of these images having been created in the 1800's, but also the actual "likelihood".