What are we looking at?

I have a soft spot for black-dial Carreras. Put a white tachymeter scale around the outside and I become quite unreasonable.

This is the HEUER Carrera 3647NT, and it is a proper beauty. The fine white printing, recessed black registers and slender steel markers give it that lovely precision of an early Carrera. Then there are those dark honey-coloured lume plots. Small details, but I could spend quite a while looking at them.

The NT dial is exceptionally rare. Its three-register relative, the first-execution 2447NT, gets plenty of attention among Heuer collectors, but finding the two-register 3647NT is hardly easier. OnTheDash makes that same point in its discussion of the black tachymeter Carreras. OnTheDash — Chasing the Grails.

I particularly like the breathing room between the two registers here. You get the beautiful white scale and all that deep black dial, with nothing fighting for attention.

What do we need to know?

Finding a 3647NT is one thing. Finding a dial this good is another.

The surface is almost flawless. The printing is beautifully preserved, and the original tritium plots are intact, with a dark, even patina. Have a look at the individual plots in the photographs: their shape, their colour, the way they sit at the tips of the markers. That is the sort of detail that makes this watch.

The hands retain their original tritium too. For me, this dial would be very hard to better.

The case is wonderfully sharp, with crisp edges and those long, angular Carrera lugs. Possibly never polished, although I would leave that as a possibility. The caseback has been polished and shows some marks.

There is a beautiful manual-winding Valjoux 92 inside, running with strong amplitude and good accuracy. The Desert Drift suede strap picks up the warm tones of the lume and comes fitted with a new HEUER pin buckle.

A very rare Carrera, and a particularly beautiful example. This one will be difficult to pack.