Now I’ve got almost all the bits. Two Bare Knuckle Black Hawk humbuckers, Schaller Hannes Piezo bridge, Schaller Flagship preamp, push pull 500k pots, capacitors, Oak Grigsby 5way, Schaller 5way & 3way, piezo volume control, battery holder, stereo jack and plate, neck with truss rod, Gotoh 510 locking tuners, 3 strap buttons, set of strings and a piece of self adhesive copper foil.
I'm still not sure about the wiring or how many volume and tone controls would be best. Also the humbuckers can be split. At the moment I’m hoping to use solderless connectors and sprung pogo contacts. The idea is to make it possible to swap out the pickups with different humbuckers, single coils, p90s etc., and maybe the other electronics if necessary but mainly to simplify assembly of the harness prior to installation into the body cavity.
The body will be made up as a sandwich. Main piece is 32mm thick and the backing is 12mm. The two body pieces will allow a total cavity depth of 29mm. As it’s made up as a sandwich, held together with magnets, I’ll be able to router grooves for longer cable connections rather than difficult drilled holes.
On the other hand maybe I should make a mug of coffee and do some more thinking before going down the pub!