I started by using the oscillating tool to remove a little more material from the overlapping corner of the two upper skins for the left wing. Then I cleaned and sprayed primer on the rib-contact areas on the skins. Once dry, I clecoed the smaller inboard skin section on top of the wing-walk plates and got started installing all of the flush rivets using the pneumatic rivet gun. I ended up using slightly longer rivets than called for by the instructions for the wing-walk area, due to my choice to dimple rather than counter-sink, but that was expected. At the end of the work session, I finished basically all of the inboard-most 4 ribs, which represents the entire reinforced wing-walk section. Although the instructions mention the option of using back-riveting if you want to achieve a smoother surface, I'm just using standard rivet bucking for now.

What's next? There are still 5 more rivets on the trailing edge flange of the rear spar that I have to figure out how to buck due to clearance issues, but I think using the tip of an angled bucking bar will help. I'm also expecting the replacement aileron hinge bracket from the service bulletin kit to arrive