I dimpled the extra holes in the firewall that are used for attaching the extra rib in the forward fuselage area. Dimpled both left and right sides.

These parts had been temporarily joined with some soft rivets. I drilled them out in preparation for cleaning and priming. Oh, I also match drilled the little channels shown here to the ribs with a #30 bit. Previously they were drilled #40.

I positioned and drilled the popup tipup mechanism housings to the ribs and then started making the cutouts necessary to service the mechanism with everything in place.

...completed the cutouts in all four ribs. I still need to do the cutouts above these where the rod threads into the rod end bearing, and that bearing connects to the popup tipup arms. Hope to get to those done in the next few days.