OK back to work!
Deck held up while tow line arrives, easier to fit and test before the deck is glued over.
So back to Superstructure.
I had to think about this for a while but then concluded the best place to continue was with the roof skin.
The reason being that this interfaces with EVERY other piece and clearly easier to fettle each of them than this in one.
I've been building to measurements rather than templates (guide only) so using this for reference.
I turned the cabin upside down on the 1.5mm ply to mark reference points that would help when joined up
I did of course run a straight edge across all the frames and sand until flat for 100% contact.
Now glued with aliphatic resin. I've left a little spare ply overhang where there is doubt.