Just replaced the seals on my F2. There are seals that run the length of the back top and bottom and one seal that runs up and down where the back hinges to the body. I also replaced the mirror seal that is the one that prevents the mirror from hitting the top of the mirror chamber. They usually get gummy and deteriorate and will leave a residue on the mirror. Do a search on Ebay and you will find seal kits fairly cheap. I used the one from Ebay ID nikoncameras.