BDSaint, welcome to the forum. Here's a quick tutorial on photos:
The gun you describe is a .38 Regulation Police, a model that was introduced in 1917. The patent date impressed into the wood is for the patented way of mounting the larger wood RP stocks to the small steel frame underneath. If you take the stocks off, you will see that there is a long notch in the steel that answers a contour in the wood. That helps mount the oversize stocks securely on the small frame.
That serial number (6439) indicates the gun was probably made about 1920-21. Somewhere around 55,000 were made before production of this model was suspended in 1940 to allow tooling up for wartime production contracts.
The Regulation Police models (which came in both .32 and .38 caliber) were built on the company's small I frame. The .38 does NOT chamber the .38 Special cartridge, but rather the shorter and somewhat less powerful .38 S&W cartridge. The .38 Regulation Police is sometimes referred to as a .38/32 Hand Ejector, meaning that it is a .38 caliber revolver built on the .32 caliber frame. "Hand Ejector" is the generic term for S&W guns with a swing-out cylinder.
Regulation Police models are not exactly rare, so there is no collector's premium for scarcity. If new or almost new in the box, they can be expensive, as any old model in new condition is. Guns in more ordinary condition are usually regarded as shooters. If this gun is in shootable condition but with only half to three-quarters of original blue preserved, it may be worth $250 or so. If it still has 95-98 percent blue, it could be up to twice that much. New in box -- I'm just guessing -- maybe 900 or eve more.
The Prewar I-frame guns were the predecessors of the J-frame guns that are made today.