This car was originally requisitioned by Atlas as a replacement/clone for the old A1G 40' steel box car originally made for Atlas by Rivarossi. It was subsequently sold by MRC and Life-Like.
I'm told that the Life-Like version may have actually used shells made in the United States by Atlas (but with a Mehano underframe and trucks). Also, some of them actually come with ice hatches in the roof (due to mold screw-ups at the factory). Now that's trivia.
I don't know what specific prototype this car might be based on (if any), but I've been told that it's at least somewhat similar to the PRR's X-29 box cars built between 1929 and 1934.