Manufactured in 1867. This very scarce Winchester Model 1866 flat side carbine features the highly desirable early features such as the Henry and King patent dates barrel marking ("HENRY'S PATENT-OCT. 16. 1860/KING'S PATENT-MARCH 29. 1866."), flat loading port cover, two screw upper tang and "Henry Drop" receiver. The barrel has the first style barrel band with integral front sight blade and an early two position leaf rear sight marked "300" and "500" yards. It has the early first pattern threaded magazine tube end cap. The left side of the receiver has the original factory installed staple and saddle ring. It has the first pattern, long, coarse, borderless checkered hammer that lacks a half-cock notch. The lever loop is the early small size. The brass crescent buttplate has a trapdoor, and the buttstock compartment contains a three piece metal cleaning rod. The left side of the lower tang is correctly stamped with a small assembly number ("1672") followed by the serial number ("15089"). Matching serial numbers are on the left side of the lower tang, stock inlet, and buttplate. The barrel, magazine, barrel bands, and loading gate are blued. The hammer, lever, and trigger are casehardened. The buttstock and forearm are both fancy grain walnut. In "The Winchester Book" by author George Madis on page 57 he estimated 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.