I spent a few hours tonight working on riveting the firewall. The first rivets I set using the squeezer along the right side of the firewall were according to the cllouts. However, I started getting unnerved by the the height of the shop heads. They were acceptable in height, but I wanted them a bit larger, so after setting a few rivets, I upsized the remaining rivets to the next size. I finished about a third of the rivets, and had to stop because I was out of shop time.