What you need to be careful with NOS tires is that the damage might be internal. The rubber/latex surfaces might look OK on the exterior of the tires but I've seen NOS tires where the bond between the carcass and the tread and most commonly, the base tape seems to be compromised, maybe because of some sort internal dry rot with the rubber and the glues applied in the factory. Maybe for short, "gentle" rides, 30+ year old tires might hold up OK, but they will never be as good or maybe as safe as new tires, IMO.
Chombi