Thanks everyone for the replies and pointing out my error! Sorry for the delay in responding, I have been waiting for a PM from Michael O'Donnell and another individual I thought might respond to this thread.
I guess I should have worded things a little different instead of "field cast". Field cast would envision somebody huddled around a campfire molding buckles. Which, as we all know, can and has been done with lead & pewter for other things as all the evidence we dig from these sites can attest to. But not the brass, this might have been done like Danimal mentioned in a local foundry perhaps. What I do know, because I have seen them, are crude looking stamped & cast buckles that (purely speculation) have possibly been sand casted to make another buckle. This was what I was trying to get to but wasn't clear and I apologize for my error in my lingo. There was a NYL (New York Legion) button found on this same site. Could it have ties to them?
Danimal, I think you are probably spot on!
Thanks again and Merry Christmas to all!!
IM