I've been working 11-12 hour shifts this week, so not much time on the RV-7. I had read where one builder had problems with his crotch strap brackets fitting between the seat ribs after the ribs were riveted to the bottom skin. I had already riveted the right brackets to its set of ribs, so I test fit that assembly to the skin. It fits well, and I don't see a problem going ahead and riveting the left crotch strap brackets to its ribs.