I repeated the Dec 7 process on the right spar, with the exception of one minor oops…when back-drilling the angle-spar-rib holes I managed to egg out a couple of them in the spar and rib. Per Van’s, the spar holes aren’t a big deal because the spar is sandwiched between the rib tab and the angle. But the rib holes were not so great either, so I took one of the spare non-prepunched holes (see this entry) for the details) and match-drilled it to replace the old rib. Problem solved.