The Carrera's a total fake. Wrong case, wrong pushers, wrong crown, wrong bezel (all 3 of them! 1/5th of a second, tachy AND MH? Heuer's not Breitling...), wrong hands (except maybe the 30 min register needle), wrong size... need I go on?

For a dead giveaway, look at the third photo down when you enlarge them. See how sharp "Automatic Chronograph" and the numbers on the registers are? See in contrast how blurred "Heuer" and "Carrera" are?

Not sure what the model was originally; and can't be bothered to find out, it's such a mess. Looking at the clumsy "Heuer" engraving on the movement base plate, I'd wager it wasn't a Heuer though.

The Autavia we've seen quite a few of, including one in for service at the TAG Heuer museum. I've seen one in the metal too and though unusual, it's much more convincing than the Carrera - I plump for original as far as these go. They never made it to a catalogue, sure, but then neither did the yachting Carreras. It happens with Heuer.

The Carrera is nothing but a desperate fake.