I went to the airfield and finished installing the regulator. I've decided to use rivets, as they're tidier, and it's not like you take the thing off regularly. Plus there was one rivet on it before, so you're going to need a drill to get it off anyway. I managed to smack myself in the face with the rivet gun when it popped off, as I was standing all hunched over the plane so as to not break anything else. There was quite a bit of blood. Still... I'll heal.
I ran the wires for the fuel level probe, but I think I've scraped the insulation off them in a few places, so I've decided to take it all out and start over - I'll also tidy up the wiring that's already there at the same time - it should all be able to go into the cable management, if I'm careful.