Today, we finished cutting out the access hole doublers for the lower tail cone area. After cleaning and priming, we riveted them in the inside of the tail cone. I drilled 3/16 inch holes for rivenuts and will dimple my access covers with my rivenut dimpler, similar to what I did for all the others. While Julien was final riveting, I worked on the firewall, marking the two upper outboard engine mount holes, then removed the firewall and drilled them to size. Next, I installed a large 3" channel horizontally across the upper firewall, with the ends centered on the engine mount holes. I'll post a picture during the next work period.