Audemars Piguet ROYAL OAK PERPETUAL CALENDAR OPENWORKED   New Audemars Piguet Royal Oak Perpetual Calendar Skeleton Ceramic Watch   The bold as well as desirable all-black ceramic Royal Oak QP is now pre-loaded with a high-end skeleton activity.   The Audemars Piguet Royal Oak and its particular all-ceramic perpetual calendar types (all black and now white) have been...