Principally to make it lighter and, believe me, if you knock the right side, which is still without chambers, and the left side, you can hear a difference of sound. I love the left one, it's gorgeous. Both my SGs (Epi and Gib) don't sound like that if I knock on them, and if I build a guitar I want to make it different from the others. So I answer your question about the neck: I'd like to make the Fender one, the typical "modern C" shape (the thinnest), I think it's not an usual neck for SGs, exept maybe for Angus Young's, ahah. And the headstock... Boh, I'm thinking about Epiphone ones, that are easyer to cut, but not for our CNC machine. My dad wants to re-build it bigger, so I'm waiting for his decision. Sure, I know it will be really difficult to join the sides, but I'll try. The plank was 1.8 mm thick, for this reason I cut twice the body. The guitar will be 3.6 mm of thickness, usually SGs are 3.5 mm, aren't they? Well, it's so minimal... I've not tested it yet. I will tell you. Me too, I'm curious to know how much wood is gone and how much will be left at the end of the work.