Ok, first I laid out the bottom front spar, pinning it into place along a straight-edge to make sure it was straight. Then I pin down the trailing edge. After that I start putting the ribs into place, not gluing them yet.
Apparently Balsa USA still hasn’t fixed the problem they have with the W-7 rib, because indeed on my kit the rib is too tall. I’ll worry about that a little later.