MC cartridge s question??

I just purchased 6 cartridges from a private estate auction sale. Four of the cartridges are 15 years old and still NIB, while the other two (1992 vintage) have seen limited use and come with their original packaging etc. I bought these cartridges for use in my future analogue system. Could you please comment on the cartridges, are they any good, etc., BTW, I paid $350 CDN for all, therefore, if I bought a bunch of crap, no big deal. Should I be worried about their age?

These were bought in 1986 and 87 and are still NIB

Miyabi Ivory
Kiseki Agaat Ruby 4.5
Shinnon Red Sapphire
Koetsu Red

These two cartridges were purchased in 1993 and are slightly used.

Denon DL-1000
Sumiko Blackheart

I recognize most of the Manufacturer's names, but none the models.

I also picked up a Classe NIL head amplifier for $50. The auctioneer did not know what it was, therefore, he sold it for the auction minimum bid.
Incredible score! I don't know about the others but I'll give you your total investment for the Red. I doubt if you'll take me up on it once you read the posts.
You are probably looking at about $10k in cartridges there. Unfortunately, they are old and they do have a shelf life, due to the aging of the rubber suspension donut. Even the NIB ones. They will still work and give decent performance, but they will not sound like when they were new. You could use them, or have them rebuilt without retipping, which would cost far less than the normal cost of retipping. Or you could sell them to someone who would do one of the above. They do have good value on the used market. They are all very good quality cartridges. You made quite a score there. Congratulations.
I'd sell them all ~10...15x and than buy a new one or even new one with the phono preamp Pass Ono for example. Lots of way to expand when you basically win the lottery:^)