Real watch collectors are a demanding sort. For them a watch is only genuine if all of the parts are original. Not only this. All of the service work must be carried out in compliance with the manufacturer, and only a complete service history protects against depreciation. Even the smallest inconsistency or discrepancy in its history or an irregular servicing can lead to a considerable loss in value. And it's even worse when it comes to collector's watches. If just one part is not original, a high-quality investment becomes a nice watch that might still be valuable, but nothing more.