tommy:
the dashboard Heuers cannot be dated by the numbers on the case (or for that matter on the movement or anywhere else). the numbers on the case may have been used or tracked by the company that produced the cases, but they were never tracked by Heuer.
as you will see from OnTheDash, there were two main versions of the dashboard Autavia. these two versions are identified by the pushers being to the left or right of the crown