I've recently gotten into vintage watches and have a couple each of Tissot, Edox, Rado, and Omega, plus a Longines and a Accutron that I'm certain are all at least 30 yrs. old-- thus, they're "vintage", rather than just "old"
Now the Omega's, Longines and Accutron were easy to date via serial numbers-- heck, Bulova's are probably the easiest of all watches to date-- they've got the year of manufacture code right on the outside caseback. I haven't been able to find a resource for dating Tissot, Edox or Rado watches, though. Can anyone help?