I just recently decided to experiment with some Kodak Plus-X that expired in 1976. I bought ten rolls for a buck, and thought it would be fun.
Last Friday I decided to go out and try it. Knowing that I would have to overexpose, I shot the film at EI50 (film is ISO125). Along with the Plus-X I shot a roll of TMax100 as well, also shot at EI50. Contrary to common sense, I semi-stand developed the Plus-X for 20 minutes, 1 minute agitation initially, and a couple of inversions at about 10 minutes. The Tmax was developed stand for 45 minutes.
The Plus-X definitely had more base fog, and was slightly denser. The Tmax is sharper, but they both print fine, but the Plus-X requires about twice the exposure in the enlarger to build similar density in the print.
If I can develop 30 year-old film with Pyrocat-HD, and you're using HC-110 which is a good developer for what you're doing, chances are you have some fine film to work with. It could also look like crap, depending on how it's been stored.
I hope that helps encourage you to have some fun with this stuff. Sometimes unpredictability helps in creating some unique prints.
- Thomas