After some consideration, I decided to make spacer to sit on top (well, really on the bottom) of F-623 to give the bottom skins a smoother transition. I made the spacers out of 0.032 and match-drilled them to the skin. I cut lightening holes to try and keep the weight down. I didn't put any lightening holes in the area where the flap pushrod will exit. I tapered the forward edge of the spacer to trasition the skin to F-605.
I also put a few tack rivets in the skin where it rolls over the F-623, this will keep everything in place for riveting the skins on.
