In this particular example, I find the explanation/backstory from the dealer to be quite convoluted (sounds like a strange arms deal) and riddled with lots of cya (must be a lawyer by training). I would think when dealing in such "rare" pieces with high price points the diligence would have been much more in depth i.e. the careful and thoughtful examination that's been alluded too as well as full vetting of the origin and source of the watch. In addition, I hope that the buyer has been made aware of all the new developments as well as the other items the dealer has mentioned in this thread because the original listing for the watch makes no mention of being serviced, a pusher having been replaced, the other marks or issues with the dial, etc etc. As
@jordn says this is a full blown franken and certainly not worth anything close to the price paid especially given the other replaced parts, etc.