From day one, the word “window” has been a problem for millions of road travelers that need a tight seal with no leaks., and no sweating. If there is one single flaw regarding Airstream trailers manufactured before 1970 it’s the fact that few open and close without the seals cracking and the frames shifting out of plum eliminating moisture.
Many frames themselves do not line up with the body and therefore will never have that necessary “air and water-tight” closure.
Once the window is tweaked, it is almost impossible to re-configure it back to perfect form which it must be to have a snug seal. We have even experimented with heating the frame slightly to fit each window. Seldom does the heated metal retain the original shape. Almost always each window reverts back to the imperfect flawed symmetry.
Since we are always working on possible solutions, be prepared for a breakthrough! I will be the first to inform the Airstream community of our success. (Call me for more help)