As for the hand? I have never seen a red one in all my years of looking at first generation Carreras. If you look at the bottom of the hand, it's the wrong shape and width for a contemporary Carrera too - my guess is it was changed at service somewhere down the line, possibly at the owner's behest. It's hard to remember everything that happened to a watch over 40 years, unless you're really into watches and all due recognition to the seller for offering the reduction, however modest, in the presence of a little doubt over originality.

It's one of the later first execution, first generation Carrera Tachys - maybe that's a distinction we should try to make in the Carrera table. The way to tell is by the scale, or rather what it sits on. In early watches, there is a distinct ring around the dial on which the scale is printed, on later watches the dial is uniform. This also applies to Deci scale watches, but not the black-dialled Tachys, which seem not to have the distinct dial ring from day 1. You can even make this out in the contemporary catalogues, but this photo should make it clearer what I mean:

I think it was Arno who sent me that originally, but not entirely sure, so thanks to whoever did!

Interestingly, with the introduction of the Carrera 30 and changes to the Tachy and Deci scales, Heuer went back to having these on a noticeable ring. Apologies to all if the minutiae of changes to Carrera dials are only of interest to me alone!