Good news! The world of firearms is such that some guns achieve almost cult status. Usually, that happens just after the model is discontinued. So it was with the biggest, heaviest M&P that S&W ever built - the fixed sight N-frame made as a platform for the then-new .41 Magnum cartridge in 1964.
Introduced as a police sidearm, the Model 58 caught on in only a few places - San Francisco and San Antonio to name the most memorable. It had a short service life and was discontinued rather quickly. A rugged horse of a gun, it was often customized into all manner of things, usually .44 Mag. or .45 Colts. I have had a half dozen of these guns and usually made something else out of them. However, the one that belonged to Rex Applegate is going to stay the way it is. Now, for all of you who have wanted one, Smith & Wesson has re-introduced the gun in their Classic series. At least for the immediate future, you can have one of these much sought-after brutes for your collection.