Holy S*$%! Now that is an awesome photo! Since this can not be proven/disproven to be Fleet Walker I'll offer this for debate:

1) I agree with the above posit. According to "Black Diamond:The Story of Negro League Baseball"... "Fleet was so embittered by his experiences in baseball that he advocated the separation of the races. Walker, was a successful writer and businessman, used his influence to promote the idea that the best chance for black survival was their return to Africa" (p. 32) In this regard, Fleet playing in an integrated game again would be unlikely.
2) He would have been 50 years old. Possible, but tough to play catcher at that age.

The school paper angle might be your best chance since even if coverage is minimal hopefully batteries are named.