Spent half an hour riveting the top surface of the left flap. As before, I had to use blind rivets for the aft two holes on the inboard rib. The annoying this is that I realise I could use MK-319-BS rivets in the existing holes and they look *heaps* better: no need to drill out to 1/8" and use CSK4-4 after all. Damn! I decided against re-doing the other side.