You want to match the date with the correct use of that date.
Here are the 3 different dates that can be found on a Gruen watch.2.
This is the standard labor involved in collecting the basics.
It is from raw data such as this that patterns begun to emerge if you collect enough of it.
It's is also the most bullet-proof of the dating techniques.
In ongoing research into Gruen watch dating techniques, Gruen researchers log everything stamped onto the watch, inside of the case, and look for a match in vintage advertising.Even if the movement is the exact same caliber as the original movement, it can have a manufacture date that differ by as much as 10 years. If it is close to the Case Manufacture Date and Style Number Date, then I feel quite satisfied with this estimate of the watch's age.In addition to learning about individual watches, the Style Numbers can teach us a lot about Gruen's use of movements in watches.This version extends the Style Number dates back to 1925!The online version (above) also provides dates for Style Numbers as far back as 1925.Yes, there are bits of information scattered here and there.