#1 son came over after work to help me get things connected.
We didn't have our act together and the first attempt, we didn't keep the longerons level, so they binded (bound?) in the fuselage and 1/2 pushed the fuselage off the table! Second time worked like a champ. Some final finagling to get the fore/aft fuselages overlapped with the skins, etc., and cleco'd it all together. Blocked-up the front as per suggestion to not put too much weight on the joint.
Next, we put the steel frame in place. Got 3 of the pre-drilled rivet holes aligned and cleco'd, but the 4th woudn't go regardless of what we did. Took it off and measured, and its hole was 2mm higher than the right side. You could also see it visually where the crossmember welds were in relation to one another.
Got out the cutting disk and filed it smooth. Re-installed and it fit well.