sean...regarding deterioration of phono cartridges over time, I think it is the elastomer (rubber) in the stylus mounting that hardens over time, and if left unused (unflexed) for a time. I can't think of anything in the cartridge body that would age.
I suspect that storing your spare stylus in the refrigerator or freezer would preserve it. Just thaw it out before use.
I suspect that storing your spare stylus in the refrigerator or freezer would preserve it. Just thaw it out before use.