My only gripes against the LeMat would be, first, it's pretty big, and second, I don't know if I'd trust any reproduction until I'd had a gunsmith look at it. I suppose that's true for any firearm to some extent, but I've had some serious problems with repros! Other than that, one heck of a weapon.
Of course, talking about how big the LeMat is, the Ruger Old Army, Remington New Army, or a shotgun are none of them exactly pocket-sized. They had many powerful weapons in the pre-metallic-cartridge days, but they surely lacked powerful pocket-sized repeaters.
So here's one for you. It's, say, 1860. What are your choices for pocket carry? You could have a Deringer or derringer, or maybe a pair of them, muzzle loaders able to put profound holes in anything, at short range-- but only one hole per pistol. Or you might go for a Colt .31 pocket revolver. Maybe one of the newfangled S&W .22 rimfires, if they were on the market yet. Or do you just plan on wearing a loose coat, and hiding a full-sized revolver in your belt or in a shoulder holster? What would you do? I don't even know what the average man or above-average pistolero did for concealed firepower back then. I'd kind of like to know.