I purchased an M1 from a friend. The receiver is marked Underwood. The barrel is also marked Underwood and has a date stamp of 1-43. The front sight is marked with a "U" and the trigger group is marked "Inland". Now here is what I am trying to find out. The serial number on my rifle is 1,870,8XX. I looked on line and one website says Irwin-Pederson/Saginaw (S'G") had a serial number range of 1,762,520 through 1,875,039 and another website says that Quality Hardware & Machine Co had a serial number range of 1,850,040 through 1,907,519 (July 1943 - Aug. 1943). So who made the rifle I have? My serial number falls between both of these ranges and it does not fall into any of the Underwood Elliott-Fisher serial number ranges. Thanks in advance for information.