Riveted the rear spar assembly together, which includes the rear spar channel and rear spar reinforcement and rudder hinges. Went well but I had to drill out one rivet. I found that riveting the spar on its side was easier from a leverage standpoint with the hand-squeezer, but it was easy to mess them up. Went on to rivet the front spar to the ribs per the plans and the next step is cleco'ing on the skin for riveting. The most important thing is to secure the work so it doesn't move around and you can keep the manufactured head seated good against the material.
Riveting rear spar and rear spar reinforcement and rudder hinge brackets
Done - the clecos block the holes that are for riveting the ribs to the rear spar