The Rolex Ref. 8171 “Padellone” Triple Date Moonphase is one of only two models of moonphase watches that Rolex has ever produced. It features a snap on back, as opposed to reference 6062 which features an Oyster screw down back. Produced circa 1950, only about 1,000 Padellones were ever made.
Available in 38 mm by 14 mm stainless steel or yellow gold case, if you can find one. This stainless steel example (pictured above) will be for sale at the upcoming Antiquorum auction April 25, 2012 (lot 172). It is in very good condition and has the original signed dial, case and movement.