Colt's First Model Derringer was based on the design first manufactured by Moore Patent Firearms Co. and then the National Arms Co. before it was purchased by Colt in 1870. They were manufactured until 1890. Colt advertised this model as the "No. 1 National Deringer." This example has flourishes of scroll engraving on the sides of the frame and behind the hammer and a burst pattern at the breech. The top of the barrel is stamped "COLT'S PT.F.A. MFG/ HARTFORD CT. U.S.A." followed by "No 1". The barrel is numbered to the gun. British proofs are stamped on the barrel. These Derringers sold well in England.