I did a Goggle image search "Beauregard Rifles" and found flags for Ruckers Brigade and Clanton Rifles. Don't know if they've
been seen before. See:

http://www.google.com/search?client=safari&rls=en&q=%22Beauregard+Rifles%22&oe=UTF-8&um=1&ie=UTF-8&hl=en&tbm=isch&source=og&sa=N&tab=wi&ei=KmWgT8-uBKesiQLw-tmyAg&biw=1138&bih=702&sei=LmWgT5vQLsKsiQKEhtCWAg