Just spent about 2 hours cleaning up this old autoloader. I figured I would share it. It is a Colt Model of 1911 chambered in .45 Auto. According to the Colt website It was manufactured in 1918 and has a mark on the frame United States Property - Eagle Head with S11 and several Letters H / S on the interior and a P on the barrel. It has a two tone magazine. This is both my oldest and largest pistol both in size and caliber. There is something inscribed on the inside of the grips - that I can see from the mag well but I have never attempted to remove the grips.