Actually I have seen a picture on the internet. (It could be wrong) but it was red on top and blue on the bottom (cav swallowtail) with crossed swords. I was thinking there should be some yellow in it but i'm not an expert on Custer's flag's. I had a family memeber ride with Custer (5th Mich Cav). But never found drawings from his diary on the flag.

Shawn