The watch's case number and model number would be displayed after the removing of the Rolex bracelet.
In the old days, counterfeit rolex were so poorly made that not even a blind chimp would mistake one for the real thing. They conferred upon the wearer an aura of tacky desperation, not cool. In recent, things become much different. The old tell-tale giveaways - sloppy printing, soft metal and cheap quartz movements that made the second hand clunk its way round the dial - have been eradicated.