Patek Philippe's very first retrograde perpetual calendar produced in series, the ref. 5050J takes its design cues from a historic ref. 96 Perpetual. The 18ct yellow gold screw-back case and domed sapphire glass mean the 5050 has far more presence on the wrist than a 3940 and just oozes vintage charm. Presented complete with additional solid 18ct yellow gold Patek folding clasp, its original Patek wooden box and extract from the archives confirming it's early production in 1994.