According to my books, the long flute began production in 1915. 1379 guns were made in various Calibers. SN: Range 330001 to 331379. This info is from David M. Brown's "36 Calibers of the Colt". Brown's book has a lot of good information, but he was know to embellish things from time to time. The Custer Battlefield with long flutes is most likely a fantasy gun.