This is actually the Army model. The only difference between the Army and Navy is the barrel selector on the hammer. The selector area on the Navy is rather fragile and I had one which had broken, twice. The Army style is a bit more solid.
I have read the same thing concerning the shot loads. I have also read that one would want to shoot it first so as not to deal with the load diribbling out the muzzle. I have never fired the shot bbl, but it does make sense. I suppose one could pack it pretty tight, but I can't help but wonder just how tight it would have to be. I have also read that ignition can be a bit spotty when the hammer falls on the center cap. I wonder if that has something to do with leverage - I just don't know the reason for that.
The ball would need to be about a .65 caliber. I've got a .69 caliber flintlock that I've played with and it was real fun. I haven't gotten around to ordering any balls for the LeMat. I think I'd rather shoot balls out of it than shot just for the ease of loading (and reloading if everything has a tendency of falling out).
I have a very basic leather holster that a local fella made for me. I've always wanted to get a repro holster, but have just never gotten around to it.