Mis-drilling the nose rib blind rivet drove home the fact that I had no way of inspecting the nose ribs once the main spar was in place. This means I have no way to inspect the blind rivets holding the main spar to the nose ribs - so the truely are "blind".
So, I checked the Canadian Tire flyer, and discovered that they had a probe camera on sale ($40, regular price $89). Sold. Once I got it hooked up to my laptop, and got the software installed.it worked great. The pictures below show the problem nose rib.
overall view - the upper cleco is in the problem hole
the problem hole. the elongation can be seen above the cleco.