Started riveting the stiffeners to the port elevator skin. I stopped after a bit because I was not getting as good results as I did on the rudder skin. The rivets are offsetting a bit when I drive them, as you can see in photo 3 of the first two rivets, so I need to take a look tomorrow at what is going on. I think I'm driving them off-center a bit. Need to look at my table and back rivet plate and make sure everything is square. I'm also thinking of driving the rivet more slowly and controlled, and then fully setting afterwards.
The first photo shows about half of the lower stiffeners riveted in place and the trim servo reinforcement plate. More detail of this in photo 2. The platenuts had to be dimpled and then riveted on the skin. These rivets all came out nice.