Rolex. An Extremely Rare and Fine Stainless Steel Automatic Triple Calendar Wristwatch with Moon Phases and Tropical Dial Signed Rolex, Perpetual, Precision, Ref. 8171, Movement No. 56'924, Case No. 686'258, Circa 1951 Automatic jewelled lever movement, tropical silvered dial, applied Arabic, square and dagger numerals, outer blue date ring, central date hand with blued steel arrow tip, two windows for day and month in English, subsidiary dial for moon phases and constant seconds, large circular case, snap on back, stainless steel Rolex buckle, case, dial and movement signed 38mm diam.