Simon you are quite right about 21 frets. I really hope I haven't managed to mess up any of my other measurements by that much..!

Sonic; I've though about building my own CNC a couple of times, but I don't think I ever will unless I stumble upon some servo motors in need of re-homing. But yes give it 5 years and maybe laser will be worth the cost of a home unit.

Small progress update.

Drilled the neck holes with a very fancy guide block!


Neck attached


And the bridge screw line marked.


I'm not sure where a normal scale bridge fits, but the original hard tail ground is still under the bridge so 12mm sounds about right.
My next problem; I have a very precise template for the bridge, and no precise way to get it into place... I have some thoughts, might do a test piece first.