If it were like counterfeiting currency, with all kinds of sophisticated devices and special materials, I'd say you are right, but no one ever in their wildest imaginings thought, when they made those bezels, that they would someday be worth the price of a good used car. If someone wants badly enough to make a perfect copy with or without patina, the copies will be made and may well already be circulating. That is the crux of the problem. Some of the bezels being traded may already be perfect copies. Consider the lengths to which determined faux watch makers have gone with the Submariner. First they had ticking quartz movements and cheap-looking dials, etc. Several generations later, only an expert could ID a real Submariner if it is one of the really good knock-offs. Even the movements are mechanical, (but can easily be identified IF you take the case back off) they have the engraving between the lugs, the markings on the rehaut, etc. When one considers how much work and cost goes into making a fake Sub that might sell for a few K, it becomes very clear the payoff with fake bezels would be greater and simpler, which leads me to believe excellent fakes are already being circulated, maybe have been for years. I expect many will disagree, especially those who may have shelled-out BIGLY for a DON. It is logical to at least accept the strong possibility of near perfect fakes.
And in response to MSNwatch: Patina could absolutely be faked.