Where can you find information about a 19 inch double barrel Riverside Arms gun with a 1914 patent marked Property of Wells Fargo on a brass plate and the initial WF on the barrel and frame?

I can tell you that your shotgun was made by J. Stevens Arms sometime between 1914 and 1940, the barrel was cut off and the Wells Fargo markings were added by someone trying to make an inexpensive shotgun appear to be a rare collectable firearm. WF guns were not marked with the brass plates and so many "stagecoach guns" have been faked that there is no collector market for any that do not have solid provinence, ie., a bill of sale from the company identifying the make, model, and serial number.