Best AD to build relationship with in London

[G-UK]

Hi there - what's been your experience with the various Rolex AD in London and which one would you recommend?

I stopped by Mappin & Webb in Old Bond and registered for a Yacht Master 37mm a few months back. Although they didn't specific timelines (expected!), they said that it was a piece that could be possible to get but 2 months later I still haven't received a call. I wonder if I should be looking into a different AD?

I bought a few Rolex before (not via AD) and I'd like to build a relationship with an AD in London for modern pieces (and to potentially tap into Patek, AP and other things at retail for when the time is right).

Suggestions? Thank you!