With the composite on the frame and sanded, I drilled all of the remaining holes. Well, almost. I still have make the angled bend in the skin on the sides and drill the holes below that level. Also...

I don't quite have enough clearance to back drill the holes nearest the gooseneck arms.

...or near the center splice plate. I have an approach to deal with this, but it's going to require a custom tool.

I bought these tiny bevel gears off eBay a few weeks ago for just this situation.

First thing is to drill the ID up from the 1mm size as supplied up to 3/32. That should be a press fit for a #40 drill. I made a little holder to clamp on the cylindrical portion of the gears in order to perform that drilling operation.

Worked swimmingly.