I remember distinctly that Patek used to sell their movements only to retailers in the early days. It was because of tax reasons and such, especially to North America.
Shouldn't there in this case be heaps of movements which are not officially cased by Pateks, and how does Patek handle such situations when they come back in for service? Would they case it with the appropriate case/dial of that era, or would that put on a modern version of those parts.
Cheers