: I contacted the dealer who informed me “Re the Swiss T etc , I
: have found anomalies before, it all revolves around legislation
: declaring the use of tritium and some dials did have it and some
: didn’t .
He's right. The rule regarding displaying a T to indicate a watch uses tritium was picked up at different times by different legislations. It began to be used a little while after the launch of the Carrera (I think the earliest countries adopting the marking began in '64 from when I looked at this before), so the watches at the start of the run shouldn't have it, then you get a mix depending on the intended market and eventually it was easier to just mark all the dials.
Feel free to link pics for comment if you have other concerns :)