Did a final check on the fit of the bottom cowl and removed it. Aligned the rivet lay-out, drilled the hinge, matched-drilled the cowl, and re-attached. ARRGGH ... somehow the left side had a 1/16" gap.
Removed and decided to mix up some epoxy and glass the holes, and re-drill.
Mixed a tiny batch, and hours later it was still tacky. Scraped it clean and mixed a 'hot' batch, and same result. Cleaned it again. Will have to replace the hardener, it's gone bad. (smells like ammonia, too).