Some info on the photographer.
https://www.ancestry.com/boards/thre...urnames.bellin
From a few other sources The address shown may have started around 1897, even though he was operating at other addresses in the 1880's.
The "A" to me isn't quite right, the left bottom curl on the Red Sox uniforms looks a bit thinner than on this one. The lace up collar lasted in Boston through 1909, so maybe later years had slightly different letters.(Photo is in the BPL)
The BA lasted through 1911 according to this.
http://joyofsox.blogspot.com/2008/12...forms-and.html
Maybe a handed down 1910 or 1911 uniform?