You have a Smith & Wesson Old Model Russian (also called) Model No. 3, Russian 1st model; in the scarce commercial variant. This revolver was identical to the earlier American Model No. 3 / 1st and 2nd Models, and the serial numbers on the commercial version were included with the continuing production of the American Model with an intermixing of serial numbers starting at about 6,000 and reaching 32,800 between 1871 to 1874. The improved hammer dates from about 1872 and serial No. 8,000.
Russian Models made for Russia were differently marked, and serial numbered in a different series, starting at one.
As you noted, your 6-shot revolver is chambered in .44 Russian, and has the common 8” barrel length. The fact that it hasn’t been cut back is big plus.
Relatively few commercial revolvers were made, as the company concentrated on large and profitable contracts from both the Russians and others. To the degree that they were available, the “commercial Russian” was exceedingly popular on the American frontier and in Mexico.
If you carefully remove the stocks, you may find the serial number written on the backside of one panel
Given this gun's history, I suggest that you get it "lettered." To do so you will need a snapshot of the gun, a full description including the serial number on the butt (or possibly the grip panel), and a check in the amount of $50.00 made out to Smith & Wesson. In exchange the company's historian, Roy G. Jinks, will research the original records (which are not computerized by the way) and send you a letter containing the details of what he finds.
This comprehensive document will contain an overview of the model’s history, followed by the details of your particular gun. This usually includes the caliber, barrel length, finish, and the exact date it was shipped from the factory, and to what distributor or dealer. If there are any special features they will be listed too. This information is often invaluable, and will usually increase the value of the revolver enough to more then pay for the letter’s cost.
Additional information on a historical letter will be found at the Smith & Wesson company website at:
http://www.smith-wesson.com/webapp/...catalogId=11101&content=25301§ionId=10504