After checking and re-checking fit, I went ahead and drilled the aft holes thru the round tube. No biggy. Except that the outside holes don't fit to the tube due to the big gap shown earlier. I still don't know what I'll do with these.
I also clamped the rib splice plate into position just to help hold the frame together while I drilled the aft skin holes.
I ended up having to drill out my splice plate and bowing up the two halves of the frame in order to lift the skin, so the frame skin doesn't hit the fwd skin upon opening. You want the frame skin to be just very slightly higher than the fwd skin when closed. I had them flush, or even lower and they hit with a lot of interference.
