Neil asked if his Winchester wrench might be 100 years old, so I did some googling.
"Real or Repro"
http://www.realorrepro.com/article/Winchester-Tools-fake-and-forged-marks-mismatched-pieces"Winchester Tools
fake and forged marks; mismatched pieces
At the end of World War I, the Winchester Repeating Arms Company was looking for new consumer products to maintain war time production levels. The company wanted items that could be produced with the same workers and equipment previously used to manufacture guns and ammunition. Among the new product lines selected was an extensive range of hand tools.
Winchester's tools, like their better known guns and ammunition, are now highly collectible and can sell for up to several hundred dollars. Forgeries of the famous Winchester trademark are now becoming more frequent. This article will discuss how to identify genuine marks on Winchester tools and detect the most common forgeries. We'll also look at "marriages" of mixed parts and pieces."