I can't shake the feeling that something looks off about it either, but I think that's just an accumulation of a number of parts that look to have been added in later servicing or revision.

I've never been convinced that any first gen Carrera, even from as late in production as this, left the factory with fluted pushers. That they were sometimes used as replacements when the original smooth pushers were unavailable during servicing I find a much more likely explanation. The crown looks a few mm too big as well, the top should sit level with the top surface of the case, more or less, that one seems to be a little bit proud of the case.

Replacing the second hand with one from an Autavia is odd. You would think that a Heuer watchmaker would know not to do that, but as the watch is over 40 years old, it's bound to have seen non-Heuer servicing at some point, as have the vast majority of our own watches I imagine. There comes a point with watches, as with cars, where specialists are probably a better bet than the original manufacturer/dealer.

The dial looks to be largely correct. It's unusual for such a late one to be marked for tritium, but perhaps they were doing different things in different markets by then, governed by export and import restrictions on radioactive material. I'm not sure I can see the grooved finish in the registers that I'd expect but that could be as much down to the photographs as anything, they are awkward things to get to show up unless you're taking photos at the same quality as, say, Paul Gavin. A question to the seller whether the original "Rillen" are still present would resolve that one.

And if someone is going to ask about those, then they should ask for the serial too. It should be high, definitely one in 6 figures.

With smooth pushers, a 6.4mm crown, correct second hand and a bit of a polish of the plexiglass it could look really nice, and contrast dials are rarer in 2 reg than 3 reg Carreras. Could be worth the punt for someone; as always, caveat emptor.