Just to add, and I dont know this to be 100% accurate but the thing to worry about most is the stylus itself. From what I have read, the suspensions (probably the right term) can become brittle with age which would depend in large part on the material they were made from and environmental conditions where they were stored (heat, moisture). The cartridge itself should last a very long time but buying NOS replacement stylii from years ago may not guarantee that the NOS stylus is good ... IOW, a stylus that was made 30 years ago, eventhough it is NOS, may no longer be good because of possible deterioration to the rubber or whatever degradable material was used for the cantilevers suspension. Again, this is going by what Ive read ... Old Cartridge usually fine, old stylus (even NOS) may not be.
Grainger or any of the other experts can feel free and should correct me if Ive been mislead but it does seem to make sense.
That said, I have had a few old Cartridges that I have purchased a replacement stylus for and they were perfectly fine. Two that come to mind are an 80's Audio Technica that I found a NOS stylus for. This was about 10 years ago now which made the replacement stylus about 15 - 20 years old. I didnt use it long but it seemed fine and sounded fine. Recently I picked up a replacement aftermarket stylus for a Shure M91ed that came off an old Pioneer PL12D table. It is an inexpensive Japanese made replacement stylus and the combination sounded very good. So, I wouldnt hesitate to use an older cartridge if a good replacement stylus can be found for it. Or, if you can somehow verify that the existing stylus is good ... which, outside of how it sounds (probably not the ideal indicator) is beyond my experience.