Coming up next are the smaller bulkheads that support the aft fuselage. They're progressively smaller hoops that define the shape of the aft fuselage toward the tail.
Here's a handy little tip. When squeezing rivets on a flange, use a backing plate to avoid gouges. The picture below is the scrap sacrificial plate that I used on the 705 bulkhead. Thickness of .032 works about right - not so thick that the squeezer doesn't cover the rivet tail but thick enough to keep it from gouging the web.