please have a look at this Heuer chronograph which I have purchased. It's a 37 mm chronograph from around 1960-1962. Is it the black chronograph 3336 which we find in the Heuer catalog from 1962 which also features the 3646 and 2446 Autavia for the first time? The only difference I can notice is that the one on the added photo which I bought has a tachymeter scale. Any other worries about the authenticity maybe? Your input is much appreciated. I have a photo of the internals. It's clearly a Valjoux allright.

Could we call this type the pre-Carrera maybe, the same way Rolex boasts with its pre-Daytona model?

As a big fan and owner of Valjoux 72, Valjoux 92 and Landeron Carrera's I also fell in love with this one the moment I saw it. "It simply had to be part of the Carrera collection".Also notice the round pushers, another sign of the Carrera about to emerge in '64? The fact that it measures 37 mm excl. crown makes it a fairly big watch for the early sixties, doesn't it?

Thanks for the input !

Cheers
Ron