Very nice photos and watches ! ... 2 of my favourite pieces from the current collection. The Calatrava is a timeless classic with its Breguet numerals, shape and size. The enamel world time (in my eyes) looks best in yellow gold, especially since the enamel detailing is wired with yellow gold wire pre firing, also like the more modern looking angular lugs and matching angular font for the city dial... although the 5131P North Pole in platinum is also another beauty (albeit I would have preferred the Patek logo on the dial rather than the bezel, although I know some members of this forum prefer otherwise ... down to personal preference, no right or wrong here