I am looking forward to hearing back from them on the serial number. The number dates it to 1905-1915 if it is authentic. I agree with other responders that the etching looks "crude" but I did find other examples online from that era and the etching matches.
Hello, I am in possession of an interesting old watch marked Vacheron Constantin and am trying to determine authenticity. I have contacted the company, but thought I would ask for your thoughts.