I believe that both these models are powered by the Valjoux 72C. These triple calendar chronos are very rare, in any version.

On the Carrera 12 Dato, we probably see four to six of those per year, counting all the variations / colors. The white-on-white is the most common; the white-on-black is my choice, as being rare but obtainable; the black-on-white is probably rare to the point of being hopeless. On any of these, be careful about Zodiacs or Clebars that may now be wearing the "Heuer" name.

On the pre-Carrera triple calendars, I would say that these are even rarer (at least if you are talking about the unmolested, genuine ones).

In terms of prices . . . I would say that any of the three shown below should change hands in the $2,400 to $3,000 range. They are all tough find . . . the white-on-white Carrera 12 Dato is probably easiest to find, and least expensive, in the $2,000 range. You will also see less expensive pre-Carrera triple calendar chronos, but some of these seem to show a lot of wear and tear.

Jeff

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: i am searching for some information about a
: triple calendar Heuer, there are two types
: in which i am interested: the carrera 12
: dato and a pre carrera triple date. As far
: as i can see, the movements are both the
: same, the pushers and hands are different.
: Is one of the two more preferable above the
: other and if so why?

: regards,

: juko