Colt D.A. 45 / 1911

I'm looking to see if anybody would have an estimated price for a Colt D.A. 45, this was on the side of the gun. The only serial number found was in the front barrel housing, the number is 191163. The bottom of the barrel says 'United States Property'. Each inside wood handle says 191163. On the steel there are the letters P/G. The patent dates look like PA TD Aug 5 1884-June 5 1900 then July 4 1905. For the age of the gun it is in excellent condition. Doesn't seem to appear blue, and does have the colt symbol on the side. Thanks any help would be appreciated.