Alexander Barter on Instagram: "This December Sotheby’s New York are selling the extraordinary Olmsted collection of rare complication watches. The collection includes some of the most spectacular watches on of the early 20th century such as this superb and massive (75mm diameter 454g) one-minute tourbillon, grande and petite sonnerie clock-watch with trip minute repetition, perpetual calendar and moon phases. It segues from the recent Breguet posts with its beautiful silver guilloché dial and p