RE: wing damage on a printed ARF
I'm doing a similar repair on a H9 Spitfire.
Don't be afraid to cut away the sheeting, that can be replaced. Just try to keep the cut lines very straight and parallel, but less than 3" apart. That way, you can cover it all over with a stock piece of sheeting when the repairs are finished. Now, the inner structure is open to you to get your hands in there (ask me how I know - my hands have been referred to as catchers mitts).
In the case of broken formers, glue back what you can, keeping it straight and true. If need be, cut out and 'sister' in some ribs or riblets to reinforce. I also replaced the landing gear rails with maple, for strength. Pilot holes will be a necessity when the gear goes back on.
My sheeting was metric, I think 3mm which makes it about .075 thick. That's too thick for 1/16" and not thick enough for 3/32" sheeting without a lot of sanding. So, I plan on laying down some strips of 1/64" ply on the bracing where my sheeting will lay.
Just my $.02
Bob