This rare Winchester Model 1866 flat side carbine features highly desirable early features: the Henry and King patent dates barrel marking ("HENRY'S PATENT-OCT. 16. 1860/KING'S PATENT-MARCH 29. 1866," faint), flat loading port cover and "Henry Drop" receiver. The upper tang has two screws, another early production feature. The left side of the lower tang, stock inlet, and buttplate have the serial number "14171," which dates to 1866 or the first year of production. The front sight blade is integral to the front barrel band. The rear sight is a two position leaf. The left side of the receiver has the original factory installed staple and saddle ring. The magazine tube has the early threaded cap correctly without a screw. The stock is fitted with a trapdoor crescent buttplate holding a three piece cleaning rod. In "The Winchester Book" author George Madis stated that the total number of First Model 1866s manufactured was approximately 3,500 guns, equally divided between rifles and carbines. He further estimated that the survival rate for these early Winchesters was about 25% and that "less than 875" First Model 1866 rifles and carbines were available to collectors" (page 57).