Can't answer without the serial number.
1919
made approx. 1917/1918
The Colt model of 1917 revolver just like the Smith and Wesson model of 1917 revolver was made from 1917 until January of 1919,for use in World War I. Another answer: 1918 specifically
The Colt 1917 45 ACP revolver serial is most likely located under the barrel or beneath the grips on the gun. This gun was manufactured in the early to mid 1900s for military use. The gun's serial number gives you an idea of when exactly the gun was made.
The Colt 1903 32 ACP with serial number 35xxx was made in 1944.
No such serial number for a Colt 25 ACP
271832
Actually, the cartridges are .45 ACP (automatic Colt Pistol) and .45 Colt (the cowboy era revolver cartridge. There is not really a Colt 45 Long. Can a revolver shoot both? Some can- they are chambered for the Colt .45 -but to shoot .45 ACP they need a "half moon clip"- a strip of metal that holds 3 of the shorter .45 ACP cartridges. 2 of those fill a 6 shot revolver. The PISTOL (not revolver) that shoots the .45 ACP cannot shoot the .45 Colt- no groove for the extractor to pull a fired cartridge out of the chamber, and it is too long.
You will have to call Colt
The revolver was actually the S&W Mdl 1917, even though most were delivered in 1918. It was made to fire the .45 Automatic Colt Pistol cartridge (ACP) but markings were .S&W 45 DA (double action). Here is a link to a good article on the revolver: http://www.gunsandammo.com/historical/wwi-wheelgun-the-sw-model-1917/
Your gun was manufactured in 1908. You can find such information on many handguns (the notable exception being S&W) at proofhouse.com BTW, in the name of privacy, "X" out the last 3 digits of a guns serial number. The first 3 will do.
made 1917