G'day,
there´s no way to transfer a given case number into production dates, but the Traveller II is discontinued since some years ago (about 2003). This may tell a bit, while specific production dates need to check the brand´s records. To do so, i´d suggest to get in touch with a GP dealer near to you.
As for papers/authentification, you´re most probably left to the person who sold the watch.
Cheers,
Peter