What you have for sale is known as a New Orleans Ace boot pistol. They were marketed under several company names but the most popular was Classic Arms Co. They come as a kit and are still sold today. They have been around since the mid 1970's (that is when I purchased mine). The receiver, grip etc. was also used on another of their kits, the duck foot which has three barrels in a fan shape. Never could hit the broad side of a barn with mine, but I made a nice little box for it and a powder flask, balls, caps etc. that sits atop my muzzle loader gun cabinet to today. Value is not very high due to the fact that the kits are still available today from numerous suppliers for less than what you are asking. Good luck with your sale.