I have a 500 sheet box of 11x14 Kodak Kodabrome II RC Grade 3 that had expired in the early 80s. I know it hasn't spent it's life in the fridge but it's perfectly usable. I had a large roll of 5" Polycontrast that had been expired by about five years. I loved that paper. Sorry if none of this helps answer your question, i've just been pretty lucky with outdated/expired paper. If the paper is bunk, you can always use it for carbon transfer printing!