I have a 2007 OB Flamingo. Yes, nice slight arch in the roof, look for water stains down the middle of the inside of the roof (also look for repainted surface) also check behind the curtains in the middle. I have a few bubbles in the outside lining of the roof, but no leaks (as tested in storms and heavy rain while camping).
We looked at a Swan is Sydney that had water damage, had been fixed but the inside lining was very soft....
Not sure about the wall frames, I may have some more info tomorrow as I have some mods planned.
I can take photos of any parts you need, just let me know...