Hi Mac! Welcome to the forum- when you get a minute, drop by the intro thread and say hello.
About your revolver- S&W made guns in different lettered frame sizes. Higher letter, Bigger frame. A little Chief's Special 5 shot snubby is a J frame. The standard Model 10 or Model 64, 65, 66 is a K frame. Yours is an N frame- big boy. Started making those in 1935 when the .357 first came out. SOME are "registered magnums" with a registry number marked on the gun- runs the price WAY up.