The 55 was introduced mostly to replace the 1894 rifle with 26 inch barrel. Many of its features were the most requested options by those ordering special order 94's. The rapid taper barrel, shotgun butt, half magazine. If your is solid frame and not a takedown it is actually less common. The majority were takedown, runs counter to every other Winchester lever. The 55 evolved into the 64. What is the serial number. I think for a while the55 had its own serials then they numbered them in with the 94 serials.