This is a Model 1816 Springfield dated 1826.  The gun is complete with an original ramrod, swivels, etc.  All the components appear to be original to the gun except the external lock parts.  The lock is clearly dated 1826 as is the top of the barrel.  The proof marks are visible at the rear of the barrel and the cartouches are still legible on the left side of the stock.  The stock is in decent condition for one of these with numerous dents and dings and an age crack or two toward the end of the butt.  My guess is the gun is a reconversion from a cone in the barrel US Arsenal conversion.  The hammer, pan, frizzen and frizzen spring all seem to be reproduction parts added to the lock plate  a long time ago.  The fitting of the parts is quite good and the lock functions great.  There is an interesting mark on the forward portion of the trigger plate, just in front of the trigger guard, the capital letters C A V are stamped.  I don't know what this is.  It could be an inspector mark or could be some sort of unit designation.  At any rate, it is a decent representative 1816 that is reasonably priced.  Sold!!