I got up this morning and primed the flap braces (only on the side that won't eventually be painted) and then riveted the flap hinges to the wing bottom skin and the flap braces. Notice how the temporary rivet holes are now filled with small-head rivets that have their flush surfaces facing out. Also visible here is the section where I removed three hinge eyes to allow insertion of the flap hinge pins, per the plans.
Here's the backside of the same area. During final assembly I'll capture the bent ends of the hinge pins with some safety wire through the little holes I put in the flap brace.
The flap brace itself is riveted to the rear spar with monel rivets along the entire length, with the exception of the three inboard-most rivets – those are Cherry flush structural blind rivets. Big, solid-looking suckers. Cool.
Here's the finished product. The alignment is correct and the motion of the flaps is smooth throughout the entire range of motion. The outermost foot or so of the hinge isn't riveted yet, since the outboard bottom skin doesn't get riveted on until everything inside the wing is finished.
Once I got the flaps on for good, I started messing around with the pitot tube. I'm planning to mount it just outboard of the rib bay where the aileron bellcrank lives. The Gretz bracket is match-drilled to the spar flange, and a piece of angle stock I cut ties it to the rib. Here's some random photos of the setup so far:
I'm not totally happy with the way the backing plate is a little bit recessed from where the skin will be. I'll probably have to make a shim from 0.020" Alclad or thereabouts.