Hi all, I picked this up on a chance, not exactly sure of its legitimacy. I'm leaning towards GAR kepi with 31 being the post number in some state. It was advertised as a 1870-80s Indian War kepi however. From what I can tell, it matches a model 1872 kepi but I'm unfamiliar with the specifics and standards of how there were 'adorned,' i.e. unit numbers, branch insignia, etc. Any ideas? Thanks in advance!