Check with El Paso Saddlery. I think they have them or may make them.
They had a sort of half flap, were worn butt-forward on the right hip. The shorter ones were (I think) altered by arsenals to take the 5.5-inch barrels. The flaps had two holes for the brass retaining stud. One was for the Colt, the other for those carrying the S&W Schofield. Some Civil War holsters for Colts and Remington .44's were probably used for a time. I believe these were also used for the transitions, cap and ball conversions to early cartridges.
I also think some outfit imports replicas fom the Orient. Maybe someone knows more. Pacfic Canvas or something like that. Many repro holsters.
BTW, I understand that the 5.5-inch barrels were used by all classes of troops, mainly in the Phillipines after the well known failures of the .38 Long Colt. They were never intended mainly for Artillery troops. Don't know how that story got started.
