In my long time of collecting I leaned one thing, go to the source,
The AD is doing what’s best for AD. Not all of course but in general,
ADs changes policy, ownership or loosing its dealership etc, all in all you can invest years and money in building relationships and get back to square one…
If you go the Patek route, I’d only do it with Patek directly or it’s owned boutique.
My 2 c.