The inner wing panels now have the top skins added, in just the same way.
Once the epoxy had set I sanded the leading and trailing edges flat, added balsa to the TE and carved a chunk out of the plywood root rib and the bottom skin to clear the undercarriage mounting (which sticks out of the fuselage root rib).
That allowed a trial fit of the wing onto the fuselage. I fitted the 1/8" dowel peg near the TE, the bolt through the root rib into its blind nut and of course the wing tube. It all fitted reasonably well so I used the fuselage as a jig to bore the hole in the foam for the short forward wing tube until it poked out of the LE foam. Then I epoxied in the sleeve, and the LE balsa with an extra dollop where it met the carbon sleeve.
It all feels very strong and very rigid.
The other end is the join line where it meets the tip panel, and that paper tube better line up with the one in the tip panel.