Sorry to ask for help, but The E-Sylum reaches more people with more backgrounds than anything else, and it seemed the best choice. Here are pictures of a medal we're trying to figure out. It's large, 82 mm, weighs 195 grams, is cast, die axis as you see it (in other words, the hand points up). We are trying to figure out who made it, more importantly when (I strongly doubt whether it dates from 1863, but maybe the 50th anniversary).

We're trying to put together a book of 150 iconic objects for the 150th anniversary of the war, and this one is under consideration, but ONLY if it can be reasonably pinned down to the years surrounding the event.