I agree that Confederate flags are much better represented in the literature. I have a pretty good library covering them, including Howie Madeus' "Battleflags of the Army of Tennessee", a couple of D. Cannon's works, and all of the Glenn Dedmondt books, plus a few others.
I make flags as a hobby and for some of my re-enactor friends. (I, too, re-enact) I've gotten pretty good a making various styles of Confederate battle flags and such, but, I have been reluctant to attempt a federal flag because of the size. I have talked myself into it, though, and am looking for some info for a starting point. I am somewhat confident I can produce a National Color, but probably won't attempt a Regimental Color because of the extensive artwork involved.
One of the re-enactments I attend regularly is in Pleasant Hill, La. (Red River campaign) I've found an order of battle for that engagement and have spent this afternoon web-browsing and found several of the unit flags that were there.
Thanks, again. My e-mail is ducknbears@hotmail.com