Spent a little bit of time priming the mating surfaces on the outside of the fuselage skins. To determine how much to prime, I temporarly clecoed the two pieces together and marked the piece with a sharpie. Then I knew where to mask off. A wipe with MEK, then scuff with maroon scotchbrite and wipe with MEK and then prime.
Only the bottom skins get a little TLC. There is no extra exterior priming on the side skins.

Some closeups for reference.