Very interesting and informative indeed. This article has learned me that my 2447N must have been from the first batch. The serial number is 53865, only 84 or something after the first production number that Eric mentioned.
I always thought mine was from 1968 or 1969. Reason for that is that the back lid is not hexagonal. My conclusion now is that it must have been replaced later during service.

It does have all the other specs. The dial has turned into a lovely charcoal colour and the subdials and chrono hand into a type of ivory white. Very nice, specialcombination. The crown is "Heuerless" and the dial is without "T"
I bought it with an original leather strap with the Heuer logo in the isde in gold print.

Anyhow, I considered this watch as just one from the colection, now it has become much more special to me. Thanks Eric!

Will try to add it to the Friday photo session tomorrow

Cheers
Ron