So I did some research and did talk to Witty. His opinion is that most of these "silver" dagger are actually zincers that have lost their finish. This one is not zinc rather all brass. So when was the silvering done? The thing with this one is all the wear is right and consistent with period wear. My feeling is that the silvering was done after purchase by the original owner. Interesting the things that still show up. Warm regards to you all and as always thanks for sharing your knowledge so freely.