Welcome to the forums from the Wiregrass! Your gun is a .38 Special Model of 1905, 4th Change, square butt K frame. It is commonly called the .38 Military & Police revolver which is how S&W marketed it from the early 1920's. Since 1899, S&W has made about 7 million of them so it is hard to find one that is rare and pristine enough to bring substantial value. Most collectors would term your gun a "shooter," meaning it has little collector value but does have value as a working gun. I'd say it would bring $300 to $350 at sale depending on where you are because gun values are regional. The magna grips on it are much newer than the gun but I would leave them on (or put on some elk stags) because they offer a much more ergonomic hand grip than the originals. This gun is the ancestor of the currently manufactured Model 10 but it has a long throw action, as opposed to the modern short throw action, and an early, less effective version of the safety hammer block. Even though it is a 1920's model, it is robustly designed to shoot a standard version of the .38 Special which today is called +P. Before WWII, S&W warranted these guns to shoot .38 High Velocity which at 1100 fps was an early version of the magnum cartridge. IOW, don't sweat the ammo. Just buy and shoot what you can get.