Great Pic! That is not one I have found online and I've really been looking...got anymore?

Yes, I am certain you are correct about the Non-Historical Part of this coat.
As it happens, I do own Josey Wales on DVD and have been going through and making sketches. Two of the best scenes in the movie for this are the "Rose of Alabama" scene where Josey takes off his gun belt and the his jacket hangs naturally AND the
"In Town" scene where you can get some great close-up's of Josy's shoulder cape.
As it also happens, my girl-friend is a Civil War Re-enactor and a wonderful seamstress!
She has promised to do some sketches for me of Josey's Coat and if she let's me...I'll post them here!
Now how about any opinions as to fabric? I'm thinking canvas of some kind but what is that color? Sometimes it looks brown and other times it looks to be a dark grey...I'm inclining toward the grey. Opinions anyone?