It's a 1st exec (longer and narrower hour markers).
Note that the H/M hands are incorrect. The lume should be about 1/3 of the hand length.
For your browsing pleasure and education have a look at many excellent samples (except the elusive N) on Mika's site: http://www.vintageheuercarrera.com/

: i was looking at this one.. .very pricey and i can't tell if its
: 1st or 2nd execution

:
: http://www.classicheuer.de/uhren-im-verkauf/heuer-carrera-12-ref-2447n/