Are you able to post some pictures? With the serial number you can search this site for year of manufacture. That search will also comment on any remaining factory records. If there are records, you can request a research letter, which may shed some light on the provenance of your gun. As for the W F & Co stamping, the probability is that it is faked.
Here is a piece of info directly from Wells Fargo website
click here
... about Wells Fargo firearms...
It is our experience that firearms with Wells Fargo identification are NOT authentic.
Wells Fargo did not distribute firearms over large areas or over long periods of time. Firearm purchases were local, and armed personnel usually brought their own equipment. Also, Wells Fargo offices did not keep many outdated records, so there are no comprehensive lists of Wells Fargo firearms.
Most important to this issue, "fakes" have been produced for decades, trading on the romance of the Old West. Firearms with “Wells Fargo”marks have become a problem among collectors of antique firearms because people add “Wells Fargo” to actual antique weapons. Of course, this is not to say that every firearm with a mark is not authentic, but it is very difficult to know whether any item was or was not used by Wells Fargo, regardless of the markings.
The best information to start with is the book Company Property by James Bartz. (Westbound Stage, 1993.)