This was a huge day at the hangar.
The first thing I did was dimple the #8 fastener hole near the rudder cable egress slot. I can see how a bunch of builders would miss this hole. After the dimpling, I got to work clecoing the aft fuselage together.
We did most of the riveting with the fuselage inverted. You can see in the picture below bubble wrap was used to protect the skin in case I dropped the bucking bar.
After a long day in the hangar, we got nearly all the rivets along the bottom and left side of the fuselage installed.