Kafin,
My Brodak P-40 profile ARF is a good example . The fuselage has a bow 1/4 inch. If put a straight edge to the outer “flat” side, touching the tail area, then there will be the 1/4 inch gap at the nose - the nose bent toward the circle center looking from the top. There was some twist in the fuselage too, but not to be concerned. I did not straitened the fuselage, I just shrinked the Monocote covering. The fuselage already went through the stress relief during the building in China, during the shipping over the sea, during the storage)) When I started the assembly P-40 I used big blocks on the fuselage sides in the nose and the tail area to be sort of perpendicular to the wing being level on the glass table top. I decided to make equal distance from the each wing tip to the tail end of the fuselage, ignoring the nose bowed . The nose was compensated with the washers under the engine logs at the front bolts. Also there is adjustable rudder to deal with the “bow “ compensation. My goal was to have a parallel alignment between the hinge lines of the wing and the stabilizer looking from the top and looking from the back. The crooked fuselage is just a solid piece holding the flying surfaces. My P-40 flies well with crooked fuselage, no bad tendencies . I can add some conspiracy theory : chambered fuselage creates extra lift during the wingover compare to the flat fuselage!))
Jerry