Hi,
I understand your point but I don't think there's any chance you'll find spare parts for modern Patek Philippe calibres out the official network.
I'm not a specialist of legel matters but I think there are rules that allow makers to sell spare parts only to selected buyers when there are specific technical contents that require buyers to be trained, skilled or whatever to do the job to the level of quality required by the company.
Perhaps not in all countries though!
Cheers
Dje