: I honestly begin to despair of watchmaker's pronouncements on some
: of these things, although I understand it is difficult when they
: have to be a generalist on the tens of thousands of watch models
: out there...

: All the early Carreras used Valjoux movements (the 72, 92 and
: 723/72c) with one exception, that being the Landeron 189
: in the 45 Datos. The first Lemania movement to find its way into
: a Carrera was the 5100 used in the 510.511 and 510.523 from
: around 1984. Lemania movements were again used in the first
: Carrera re-issues by TAG-Heuer, until Swatch squeezed the supply
: of Lemania movements to non-Swatch group brands.

: Secondly, all these early Carreras had the Carrera name on the dial
: (above the Heuer shield), again with one exception, that being
: this time the 12 Dato triple calendar watches.

: Thirdly, that's not a Carrera case. The angle and detail of the
: lugs is wrong for the Carrera case, but it does look like the
: economy models that were sold alongside the Carrerras at the end
: of the 60s/start of the 70s. Check the two watches at top left
: in the picture below for similarities:

:
:

: That ties in with the Tachy scale on your watch, as Heuer had been
: using a different style until this point.

: If you look closely, you'll also see those watches have a
: distinctive internal bezel, used for measuring fifths of a
: second. It's missing from your watch but that polished ring
: around the dial makes me think it was once there but has been
: removed at service - the markings on the bezel can fade or
: break, and I have seen a few watches where it has been removed
: for aesthetic reasons. For me, even a faded internal bezel looks
: better than none, so that's something you might look into
: getting back onto the watch if it's important to you.

: So we have what looks like one of the 73321 watches of circa 69-71.

: Except we still have a couple of mysteries here. Firstly, I am only
: aware of the economy watches being made in two-dial versions
: rather than your three-dial watch. That would make it rare in
: itself. But you can help us out here - by this time, Heuer had
: adopted a practice of engraving the serial number between the
: top lugs and a model reference number between the bottom lugs
: (earlier watches just had a serial # between the bottom lugs).
: If you can tell us these numbers (you may need magnification to
: read them and they are sometimes removed by cases having been
: polished), it will help with both dating and in identifying the
: model in question.

: Secondly, there's that Lemania movement. A movement photograph
: would be brilliant to help us identify exactly what movement
: we're talking about. I am aware of 3 possible three-register
: Lemania movements it could be, but a photo would help settle
: that. And a request to the other OTDers - does anyone have a
: 73321 to be able to check what movement it uses?

: If we can get the above information, I believe we can get to the
: bottom of exactly what you have there and better be able to give
: you an idea of its value - and I do like to have a mystery or
: two to investigate!