Welcome to the forums from the Wiregrass! Your Mod. 17-3 is also known as the K22 Masterpiece target revolver, as Abby's Dad notes above. This is often shortened to the K22. The original gun was introduced in 1940 (the K22-40) and only a few were made before WWII. After the war, S&W brought it back with a top serrated rib and also made matching Masterpiece versions on the K frame in .32 (Mod. 16) and .38 (Mod. 14) caliber. These guns are nearly identical right down to the weight so a target shooter could alternate calibers without having to compensate for changes. Arguably, it is still the finest target revolver ever made. Congratulations on your inheritance!