It means it was made for commercial sale as oppose to the ones made for the government ( ie: military )
It was made in 1952.
About 1952.
Model 1911a1
Your colt 1911a1 was made by colt in 1945.
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.