Whatever box first Heuer, and then the dealer, had to hand seems to have been the order of the day to be honest. Not like today where box A goes only with watch B, and never shall be parted, they don't appear to have given the same weight to the boxes. I think the long, "cigar" box was probably the intended one.
"Plain" (i.e. no-scale dials) seem to be more prevalent on the Carreras but for Camaros, where the range of scales was not as wide, we do seem to see plenty of tachys. I've not studied it seriously, but if someone said it was a 50:50 split on Camaros, or even in favour of Tachys, I think I'd buy it.