This 18k gold perpetual calendar Patek Philippe 2497 is offered in the Important Watches auction on 9 November at Christie’s Auction House Geneva. It is the one and only known example of this reference bearing a previously never before seen military-style black dial with luminous Arabic numerals and luminous Alpha hands — all these features being unrestored and in original condition. This timepiece features one of the most distinguished provenances ever seen in an auction room. According to our research, it was commissioned in 1954 as a gift for Ethiopian Emperor Haile Selassie, and presented during his official visit to Switzerland in November that year. – Christie’s (See more details here)