The headplate veneer/laminations are done separately.
The neckthru starts off as a long rectangular 'blank' of the desired woods. The aft section (the body) is eventually left flat. The neck (angled down from the body) and heel are revealed, as is the head (angled down from the neck again). The headplates are glued/pressed on at this point, sawn fo the rough shape, and then the neck/body/head goes on from there (adding the fingerboard and body wings).
This is just the 'rough' outline of the building of the neckthru. If you consider JUST the necktrhu, it's an amazing piece of work: flat at the body, smooth heel, great feeling neck angled down and away, angled head, truss rods, fingerboard.
Did I get this basically right, VV?
J o e y