Dave - looking really nice. Love the intricate fuel pump and lug nuts. Love the 5-point harness, too.
I don't see it on your car, but the same circa FC kit I'm working on has an electronics box just behind the fuel cell. I've got everything wired to it. I would guess a real small junction box box could be added to the frame. I've attached a photo here. Not all of the wires are running to it yet.