Simon,
Been busy finishing other builds. ...... and I was worried I would throw this one across the room.
I rewired it completely to the piccy from McCreed on his response to this thread.....I actually printed the piccy out and soldered up that rig.
https://www.buildyourownguitar.com.a...ad.php?t=11419
I have taken an oak Grigsby 3 way switch out of the harness and put the flat plastic kit one back in place and got the same story. I changed the volume pot.....and the capacitor.
The only things I have not changed are the jack socket, tone pot and the connections to the pickups......maybe take it all out and rewire the lot from scratch.