If you examine the wing very closely, the join line is a little more apparent on the port wing than the starboard, but it’s pretty close.
I tried a few things, including pinning with a bit of round brass stock, but I was having a hard time getting the holes lined up exactly.
What I finally ended up doing is taking some .040 styrene strip and cemented along the join on the inner side in a kind of tongue and groove situation so the outer wing would have more surface area to grab onto. Before mounting the outer wing, I reinforced the tongues (is that how you say it?) with 5 minute epoxy, to lower the risk that they would fall off.