I have a 3 register Carrera with exactly the same case back with numbers 571## between the lugs at 6. I will take some pictures and post them in morning.

Cheers!
Amran

: Hi again Mac.

: Yes, it looks like a Carrera 2447/3647 case, from as early as 1964
: to potentially as late as 1970 in the case of the 2447.

: The caseback is more of an open question. I have seen an
: early Carrera offered once before with this caseback, but the
: vastly more common style is a stepped, flat caseback, like this:

:
:

: The Carrera was launched in the same year as Heuer acquired
: Leonidas (the aforementioned 1964), which muddies the waters a
: little. The caseback on your case is stamped Ed. Heuer (i.e.
: pre-merger) whereas the one I linked is Heuer-Leonidas SA (so
: post-merger), but we do sometimes see Carreras with pre-merger
: movements and cases - on my part, I believe they would have kept
: using parts from stock until they ran out rather than junking
: the Ed. Heuer-stamped pieces, because that makes much more
: commercial sense.

: The caseback looks genuine, not questioning that, only whether it
: belongs with that particularly case. I believe the 404 (one of
: the pre-Carreras) used this style of caseback, but I don't own
: one to check. So I guess it's possible that very early Carreras
: did use this style, or it was used in pre-production, but it's
: not what we usually see - sorry it's not a definitive answer.

: Mark