Me and my dad were just at a gun show. They had a box set of butler .22 short single shot derringers. The numbers matched. They were in fair condition and had sequential serial numbers. The box came with them. One had a mother of pearl handle with a bronzed steel barrel and frame. The other had a wooden handle with a brass frame and blues barrel. I have a couple of questions. Does anybody know anything about these derringers and this brand? And what would be a good price for that?