My great great grandfather and great uncle were members of the the 40th MS Inf. Co B (Standing Pine Guards). I would like to put together a Kepi in their honor. From what I can tell from this forum, by the time the 40th was assembled, there had been many uniform changes and sometimes the men might have just worn their civilian clothes anyway. I have noticed that many of the online suppliers of civil war enactors offer brass cap devices with regiment numbers and Company letters as well as a small bugle device representing infantry.

My question is, would it be authentic to put a "40", a "B" and a bugle on a plain gray kepi? If so, where on the Kepi would they be placed? On the Front? on the flat top?
I have also seen gray kepis with colored bands representing branch of service but it seems that these were infrequently used?

Thank you for your assistance, and I apologize if these are dumb questions!