The Patek Philippe ref. 5004P combines a split-seconds chronograph with a perpetual calendar and, in many ways, marks the end of a great era of watchmaking. For us, it is one of the true holy grails of neo-vintage Patek Philippe.

The ref. 5004 descends from a long and extraordinary lineage of Patek Philippe perpetual calendar chronographs. It follows in the footsteps of the legendary ref. 1518, the ref. 2499 and, eventually, the ref. 3970. Yet the 5004 managed to take this already formidable combination of complications one step further by adding a rattrapante. They experimented with this combination before, but never in regular production. The extraordinary ref. 2571 of the 1950s combined a perpetual calendar with a split-seconds chronograph in just a tiny handful of watches, while the unique ref. 3973 was created decades later for Philippe Stern. Both can be seen as spiritual predecessors to the 5004, but neither was a serially produced reference.

That changed with the 5004. Introduced during the 1990s, the ref. 5004 became Patek Philippe's first regularly produced wristwatch to combine a perpetual calendar with a split-seconds chronograph. Despite its relatively modern production period, it feels remarkably vintage today. Its 36.5 mm case, pump pushers, manually wound movement and traditional dial architecture belong to a very different era of Patek Philippe. Its successor, the ref. 5204, would grow to 40 mm and introduce an entirely new in-house movement. The 5004 therefore sits at a fascinating crossroads: technically extremely sophisticated, yet executed with the proportions and character of Patek's great vintage perpetual calendar chronographs.

The rattrapante chronograph adds another layer of mechanical complexity. Instead of a single chronograph seconds hand, two hands sit perfectly superimposed over one another. Start the chronograph and they move together as though they were one. Press the button integrated into the crown and one hand stops while the other continues running, allowing two events that begin simultaneously to be measured independently. Press it again and the stationary hand instantly catches up with its partner. Seeing that hand fly across the dial and reunite with the running chronograph hand remains one of the most satisfying mechanical tricks in watchmaking.

At its heart is the manually wound Patek Philippe calibre CHR 27-70 Q. Its origins lie in the Nouvelle Lémania 2310 architecture, but Patek Philippe extensively reworked the movement to accommodate both the perpetual calendar and the notoriously demanding rattrapante mechanism. The result is a traditional, beautifully hand-finished movement from the Philippe Stern era, complete with column-wheel chronograph construction and the elaborate levers, clamps and springs required for the split-seconds mechanism.

Patek Philippe has never officially disclosed total production figures, and the often-repeated estimate of around twelve watches per year appears to understate actual production considerably. What is certain is that output remained extremely limited for such an important reference, particularly when individual dial configurations are taken into account. This particular example was delivered in 2006 and is housed in platinum, arguably the quintessential metal for the reference.

The case is one of our favourite aspects of the 5004. Its proportions are wonderfully compact considering what is going on underneath the dial. On the right-hand side, the oversized crown, incorporating the split-seconds button, sits between two traditional pump chronograph pushers. The unusually large crown gives the 5004 a distinctive profile and immediately separates it from the 3970 from which much of its design language evolved.

Turn the watch over and the sapphire display back reveals the calibre CHR 27-70 Q in all its glory. The watch is additionally accompanied by its solid platinum case back, allowing the owner to choose between admiring the mechanics or wearing the watch in a more traditional closed-back configuration.

Among the different executions of the 5004, the black-dial platinum watches have developed a particularly strong following. This example is fitted with the beautiful -033 dial, featuring brilliant-cut diamond hour markers and a single baguette-cut diamond at 12 o'clock. Against the black background, the diamonds add just enough presence without disturbing the wonderfully complicated lay-out of the dial. An interesting detail is found in the indications for the 24-hour display and leap-year cycle. On later executions Patek Philippe used contrasting white indications to improve legibility.

This example remains in very strong condition. The faceted lugs are beautifully preserved and the important platinum hallmarks remain clearly visible. It is accompanied by its original box and papers, the big book, additional solid platinum case back and corrector. The watch is fitted to a black Patek Philippe alligator strap with its correct Patek Philippe folding clasp. Additionally it is presented with another strap and platinum pin buckle.

For the serious Patek Philippe collector, it is difficult to find a reference that combines this much history, mechanical ambition and old-school Patek character in one watch. The 5004 may have been produced in the modern era, but it belongs to a school of watchmaking that has already disappeared.