The above gun has all the makings of a 1917 Colt 45 ACP revolver. Some had the markings removed from the bottom of the butt frame. Also the lanyard loop has been removed and filled in. Does the barrel have the 45DA markings?
The Colt m1917 was chambered for the .45 ACP Cartridge with the use of partial Moon Clips.
The Colt m1909 was chambered for the Military version of .45 Colt Cartridge.
Thus, the m1917 will have a much larger space between the Cylinder rear and the Recoil Shield portion of the Frame since it had to oblige the Moon Clips and semi-Rim thickness combined, than would the m1909 which had to oblige only the relatively thin rim of the .45 Colt Cartridge between Cylinder and Recoil Shield.
What is the Serial Number of your Revolver, as it appears in the inside portion of the Crane Knuckle area?