I've been looking at a listing on the revolver it's stating the gun is a 1947 production. Unless I'm misreading the 4th edition this model didn't come into production until 1949.

They is no picture of a ser# it's 4 screw in pretty nice shape.
I'll probably need to call these people and see if I can get a bit more info.

correction I just went back and looked at some more pics and it's a 5 screw.

Those Pre 18's are much sought after. I have one I picked up for a mere $400 a few years ago. It's about a 95%er from 1952. All matching numbers. Watch the stocks for the correct number. It is important when evaluating any S&W. Big Larry