Here is an excerpt from a great information site:

railroadiana . org

In addition to the above, a variety of items marked Wells Fargo and Company "San Francisco Division" or "PROPERTY OF WELLS FARGO & CO EXPRESS S.F. DIVISION" have recently appeared. This marking is always on a small brass shield shaped "plate" that is soldered on the item. ALL items with this mark are recently made fantasy items. Technically they can't be called reproductions, since Wells Fargo never issued authentic items with this mark to be "reproduced". Below is a list of items found with this phony mark:

• Brass spittoon or cuspidor, weighted bottom, may have soldered tag or embossed marking;
• Large iron lock;
• 10 inch tall brass oil lamp;
• 14 inch tall candle lamp with brass base and brass top;
• Brass telescope;
• Brass hanging oil lamp;
• Leather money bag;
• Watch fob (the shield by itself with a small loop at top for the strap);
• Match or business card safe made of brass.
• Metal "strongbox"
• Wooden box containing gold scales

Due to the cheap quality of these items, the shield apparently comes off easily, and certain enterprising individuals have resoldered it onto other items to make them instant Wells Fargo "antiques". These items include: A trumpet, brass scales, and a rifle where the shield was applied to the wood stock (this item sold for over $1500 !!).

These item continue to bring big prices today from unwary bidders.