I found this several years ago and it's sat on one of the shelves dedicated to books on the war since I bought it. I've never put much thought into who he was, where he fought, and the men he fought with. Unfortunately the only real distinguishing feature in the image is has bandana.
You could talk to the Weymouth Historic society (781) 340-1022 to see if they could help you (Braintree too, next door an possible location of Weymouth Landing, but I'm not sure).
Lemuel Wallace Cook had a studio at Weymouth Landing from 1869-1886. There is, apparently, a single mention of him at Weymouth from 1864. But, he does not appear in directories until '69.