Working without details on the bottom skin. I lloked at pictures of CX4's and found a good pic of the CX5 prototype during construction. The trick is to not prevent the skin aft of this location from forming a curve to the F8 bulkhead. As seen in the photos, this skin also forms the bottom wing skin just outside the fuselage. Very important to make sure the longerons are square to the spar before drilling as this locks in the geometry. Also, the rivet holes on the rear spar were drilled with the fuselage upright on a flat table to make sure the bottom skin formed a flat wing bottom.
I ran out of energy before drilling all the holes through the double stack longeron. Will complete in a few days.
