RE: Pfalz DIII resources -- Photos, Drawings, Plans, etc.
Carpenters glue really should be clamped tight to get into the grain to be effective. I was thinking a really thinned out epoxy would work well with immediate adhesion, dry fast enough and give added strength with 1/64" ply. I haven't tried polyurethane glue yet (Gorilla glue), but it looks like it would be a good one to try and I think it would be light and extremely strong.
One method I use to build light is to add stringers like a Guillows kit and thinner sheeting over it. The stringers support the sheeting and the sheeting adds strength. I also use the stringer method in wing construction to keep scale rib count, run stringers down the length of the wings. Only every other few ribs will be full ribs and the others are square stock strings across the top of the stringers imitating ribs. Works well for false ribs too. Sometimes I use sheeting on the leading edge, but under the false ribs. No one will know but you and it will look very scale from the outside.
You could also sheet it with slightly thinner balsa and glue one layer of 1/64" ply on it.
All in all I think you will have to stick with conventional balsa sheeting to keep it light but in the cockpit area to you could have 1/64" ply where it would be visible.
I was thinking the same about the upper wing cut out on the Polapink plan
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