It will be for the M1903 colt. Here is one on GB.
http://gunbroker.com/Auction/ViewItem.asp?Item=35533912
It was a rather short lived gun in arsenal. Experiences in the Philipines against the Moros quickly taught the army that .38 was insufficient and it was replaced by the .45 long colt M1909. The M1909 was replaced by the M1911 colt automatic. In 1917 the M1909 was reintroduced as the M1917 to supplement the short supply of 1911s needed. The first 50,000 or so were chambered in the Long colt, but the remaining 100,000 produced were done so with stepped chambers to allow the firing if .45 acp without half moon clips.
The pattern for the M1903 holster remained unchanged through M1909 and M1917 models, except the latter two were increased in size to accept the larger New Service Model frame they were based on. It is designed to be carried "butt forward" on the right hip and was not intended to be carried left handed.
Value in the USA would be from $75 to $500.00, depending upon condition. based upon the pictures, it is hard to judge, but the if it is as stiff as it looks, nipped and cracked, you are looking towards the lower end of the values.
