Hi Steve,
I am going to be building a case for a pair of dueling pistols very shortly and may have some information that might help you. I must confess that most of my information is from "book learning" not experience, but I have handled 3 pistol cases, all English and from the late flint period. Of the cases I examined, the sides on one were mitered, 1 was finger jointed (not a dovetail), and the other was butt jointed. All were glued but the simple butt jointed case was also clearly nailed. The tops an bottoms were simply glued to the sides but I am pretty sure that one was rabbitted so that it had a shoulder that fitted down into the sides perhaps as much as 1/4 inch. All of the cases were mahogany and mounted with brass fittings. The hinges were stop butted at about 100 degrees of opening. The internal partitions (of the English style not French) were glued to the bottom of the case and in one case the ends were fitted into very shallow slots in the side trim on the inside of the box. The side trim stuck up about 1/4 inch above the lower half of the case to form an internal lip when the case was closed. Internally the cases were about 18" long, 7" wide, and about 2.5-3" deep. Wood sides were 1/2-5/8" thick. The partitions appear to be tapered toward their tops so that the bases were about 1/4" wide but the top was maybe about 1/8". That probably was done so the baize fabric would roll over the tops and not create a bulky bunching up. It also creates slightly tapered partition walls in which the rounded gunstocks cradle nicely. In all of the cases it appeared that the wool baize fabric (not felt) was placed on the bottom of each well first and the partitions were covered separately so that a joint in the fabric shows on the bottom of each partition. I think the baize fabric was glued down using "pearl glue" which is melted in a pot and remains pliable but sticky when hot. I am planning to use 3M Super 77 adhesive, although I am not excited about the fumes that stuff produces.
Hope the info helps,
dave