Hi Curtis,
A few non-Goldpfeil collaborations that I've heard about:
Vincent Calabrese: Blancpain, Bell & Ross
Paul Gerber: Franck Muller, Fortis
Fran?ois-Paul Journe: Harry Winston
Vianney Halter (Janvier): Audemars Piguet, Breguet, others
Antoine Preziuso: Breguet, Harry Winston
Best regards,
Stephen Sugiyama