The leather seats and gear knob look retro-fitted to me - the steering wheel doesn't have the matching orange bit (hand brake should be orange too if it's standard, no?) - and no Bose either; ergo it's not a GT.
5 points minus 1 for the steering wheel because I'm not sure I've seen a facelift with the matching alezan on it.
Alezen was standard on non-GT pack facelifts and I had to pay extra for it on the GT model I bought in December 2006 ! And my steering wheel did not have the Alezan on it but never quite sure whether that feature was dropped with the facelift upgrade or they simply ran out of s/wheels with that feature
2006 Facelift brochure attached to help the understanding.
Nissan_350Z brochure.pdf
Thats crazy, if not a bit backwards
That brochure lists the cloth seats, though and never mentions them or the alezan after page 6, plus the OP mentioned that they were retro-fitted on his. Are you sure they were standard on NON-GT's?