There is a thread on here from 2011 with some information on Jessop Pan 100, which was most likely from Valca or, perhaps, Negra. (I think that I may still have some similar film from about 2000 in my freezer).
As with all outdated film, the results depend to a great degree on the storage conditions, particularly any exposure to heat or damp, but, in principle, there's no reason why you should not get usable results from a 20 y.o. B & W film. I'd try it out.... but just not for my daughter's wedding pictures....