I just won a 500ct box of Old Grade 4 AZO paper on eBay.
I don't remember where I read it but if I remember correctly there is little to worry about when buying Old AZO.
The auction description says that the paper is still sealed in the inner bags. My only concern is the paper being fogged from age.
If this is the case is there anything that can be added to the developer (I'm planning on using Simth's Amidol) to help?