Ron,
My ancestor George Harris Camp was in Company K. He was 17 or 18 years old. I don't know all the details of the Battle of Antietam, but he was wounded by a shell and captured there.
Do you have any letters or information on the uniforms etc. I know that my ancestor carried a Bowie knife and a six shooter as well as a Springfield rifle. He was said to be an expert shot with a rifle by his son, my grandfather.
I know that a few Palmetto SS troops were mixed with GA sharpshooters on the hill above the Burnside bridge and others were in regiments fighting behind a stone wall.