The chem might be fine, but regarding the paper ... don't even bother. Six months out of cold storage and it develops severe crossover.
A year old it's worthless. But the polyester sheet is itself useful for various projects. I've saved odds and ends of old Cibachrome for making
cutout masks for negative carriers, groundglass viewing masks for reduced formats, etc. Or you could use the sheets as a substrate for
coating some kind of homemade emulsion.