1970s Audemars Piguet Ultra Thin Automatic 18k Yellow Gold 5420A stunning 1970s Audemars Piguet Ultra Thin "Automatic" in 18k yellow gold. This example comes with a no lume gold brushed dial and matching thin hands. The watch is in superb condition, showing only light signs of wear or minor scratches, which are to be expected for a piece of its age. The Audemars Piguet Ultra Thin Automatic 18k Yellow Gold Reference 5420, produced in the 1970s, epitomizes the brand's commitment to elegance and mechanical