{"reference": {"slug": "breguet-4538", "brand": "Breguet", "ref": "4538", "model": "Triple Calendar Chronograph", "case_material": "18k Yellow Gold", "provenance": "extracted_from_auction_comps", "url": "https://mostexpensivewatches.net/reference/breguet-4538", "description": "The Breguet Reference 4538 is a triple calendar chronograph produced during the 1950s, with approximately 15 to 20 units manufactured in 18k yellow gold. Collectors prioritize this reference for its Valjoux 72C manual-wind movement and its 36mm three-body case featuring downturned lugs and rectangular pushers. The dial typically displays day and month apertures below the twelve o'clock position, a peripheral date scale, and three sub-dials for running seconds, 30-minute, and 12-hour counters. Due to its limited production run and historical significance as a mid-century complicated Breguet, the reference is rarely seen at public sale. Secondary market values generally fall within the mid-to-high six-figure range. A notable example sold at a 2016 Phillips auction for 389,000 CHF, highlighting the premium placed on original dial condition and the rarity of the yellow gold configuration compared to contemporary steel models."}, "listing_stats": {"count": 0, "median": 0, "low": 0, "high": 0}, "listings": [], "auction_lots": [{"slug": "breguet-4538-2016", "brand": "Breguet", "reference": "4538", "model": "Triple Calendar Chronograph", "case_material": "18k Yellow Gold", "hammer_usd": 75000, "year_sold": 2016, "venue": "Christie's Geneva", "lot_summary": "An exceptionally rare triple calendar chronograph from the 1960s, sold to Cartier in 1969, featuring a playful dial design with an outer blue date ring.", "source_url": "https://www.christies.com/en/lot/lot-5991300", "provenance": "ai_generated_grounded", "url": "https://mostexpensivewatches.net/auctions/breguet-4538-2016"}]}