Great find Yak! Congrats!
I can only offer this. In the center of my town was a high vantage point that looked over 90% of the town. The Union occupied the town and placed artillery on that hill. Folks have found all kinds of primers and bullets, I've found dozens of ration tins and the owner found, what was left of, a Union Uniform Tunic. He was raking leaves and pulled up a faded piece of cloth with a button. I found the ration tins and what was left of a blinder button. probably from the blinder of a horse that pulled an artillery caisson. Just under the brassard should have been a steel disc about the size of a silver dollar. It seems the polished brassard was a target for the local forces to stop the removal, and thereby capture, Union cannon. If Civil War I believe you'll find a disc like this but perhaps earlier in the war they didn't use them. The event I refer to was May 23, 1863 and the beginning of Stonewall Jackson's Valley Campaign. Unfortunately for the Union forces John Mosby knew where to cross the river in the 10% of the town not visible from the artillery position.
