Thanks for your reply.
I appreciate your input and your opinion.
However, I maintain my belief in the 'On The Dash' photos and support for my watch.
I understand your comments about age, but you are saying that the movement is too early but the case might be 1980's.
As I understand it, the Valjoux 72 was made in many variants. An variant was the Valjoux 72C (also known as the 723) which was a day, date , month moonphase chronograph. This only became known as the Valjoux 88 in later years.
It is entirely possible that Heuer used this movement (72C/723) in a alternative case, either earlier or later than the usual suspects.