Unless there was a change, I thought that Pan X referred to Panatomic X, the fine grain film that was rated about 32 ASA. Plus X is a ASA 125 film. I think they quit making Panatomic some time ago, which may be the reason for the cold storage.(posted 8852 days ago)I would guess that if you give it good exposure for the shadows and test a couple of rolls to get the development for the highlights, you ought to be OK.