Excellent responses so far. Indeed, we may never know which actually came first.

But when we look at the evolution of Heuer dials, and especially this beautiful watch that Jan posted yesterday (shown below), it seems to me that the Tachy-on-dial version represents an earlier look. The style of the numerals on the Tachy scale; the lume on the dial; the thinner markers . . . all these elements point to this being an earlier "look" than the standard "Rindt" / "Andretti" dial.

Thanks for these insights!! As always, the information and insights developed by this community are absolutely amazing!!

Jeff