Does anyone recall when Ilford changed the designation (and, presumably, the formulation) of FP4 to FP4+? I recently discovered an old, exposed roll (from a bulk load) accidently left in with a bag of ancient, funky film cans. It came out very thin and fogged, even though I added 50% to the development time for FP4+. It may be too thin to print conventionally, so I may have to have a buddy scan any interesting frames for me, and print it that way. I have a hunch this roll may date back to the mid-70s, but won't know for sure until I can see a contact sheet. Most of it seems portraiture, and I'm hoping I can identify the subjects.