Ed, as always, I am away from my "sources" (being at work is a pain, isn't it?) but I believe that the "IC" is the maker. I will try to remember to look tonight and let you know. If I forget send me a PM. I will say that "U.S. Military Flintlock Muskets, and Their Bayonets, the Early Years, 1790-1815" by Peter A. Schmidt is a good place to start. He has much information that previous researchers missed or ignored.