Before going any further with the wing wiring, I realised I needed a way to mount the temrinal strip in the underfloor space, adjacent the wing root. I spent ages contemplating different options and ended up with the simple bracket shown in the first two pictures below.
The bracket screws into place under the floor, and is dropped down slightly with a couple short spacers on each side (not visible in pictures). This leaves the terminal strip atr a nice working height, and also allows plenty of room for the wiring to run underneath, and through.
I ended up with all the wiring from each wing terminated into the two strips (one each side).
My prototype bracket for mounting the terminal strip
The bracket and terminal strip in place at the left wing root
