This rare, yellow-gold 3940, with Englishdial (from 1987) perfectly illustrates why thereference is so coveted. Understated both in styling and case-size, it carries ahighly-desirable 'first-series' dial, with recessed sub-dial registers. With its modest (by today's standards) 36 mm size,and svelte profile matched by a slim, micro-rotormovement, it's arguably one of most elegant offerings of the modern Patek Philippe era.

The dial has three registers, with the various functions neatly balanced out. The sub-dial at three o'clock shows the leap-year counter and the months (in English), in a slightly recessed sub-register, giving depth to the otherwise lightly-brushed, opaline dial. This style of sub-register is unique to first-series dials. In a similar fashion, the months and day/night indicators are placed at nine o'clock. The stunningmoon-phase is placed at six o'clock, with the days of the month around it. Thegold dauphine hands add a touch of sharpness to what only can be described as a beautifully executed dial. Like the recessed subsidiary registers, the classic 'Patek Philippe' lettering also differs on first-series dials, using an earlier font type which is slightly narrower in height and longer in width. The overall look is perhaps the most refined and subtle of any 3940, without compromising functionality.

Representing the best of Swiss design, the movement itself is no less a technical feat. This example has asolid caseback, concealing the fantastic hand-finishing, theGenevian coat of arms and stripes, as well as the off-center, 22k gold micro-rotor. The ultra-thin, self-winding 240 Q base movement has been used by Patek Philippe since the 1970s, and continues to beat at the heart of their modern perpetual lines All of this (for the first series), concealed within a solid yellow gold caseback, hiding away the true beauty of the movement in a very elegant and traditional fashion.

Perpetual calendars are the authoritative complications of calendar watches. It's one of watchmakings true grand complications, and when created the in the mid-80s, perpetual calendars were scarce. With it, astandardfor all modern perpetual calendars was established. Timeless, elegant and discontinued - the reference 3940 is an investment for life, to be worn - and appreciated, daily.

Viewings can be arranged in Central London by appointment.

Closer look