About 1986. Auto Ordnance is now made by Kahr- you can contact them thru their website.
An Ordnance Serial Number is the serial number assigned to a piece of ordnance, such as a rifle or artillery, etc.
Model 1911a1
Your colt 1911a1 was made by colt in 1945.
You need to tell us what model of what firearm. Auto Ordnance made a .45 cal semiauto carbine and a 1911A1 pistol.
Serial number
That is not a serial no of a Remington 1911A1 they stopped in 1945 with 2465139.
1945
In 1918
About 1943.
1943 by colt
made about 1917
Made in 1941.