Are they still gonna be good? They pass a visual inspection, have been stored in the dark etc. How long can I expect them to last?

 

I wouldn't use them. Rubber starts deteriorating after 6-8 years. They may look OK, but I'd bet they aren't. They could be used for roll arounds if you are doing restoration or need to move a car around, but I wouldn't put them on a streetable car.

 

only have 500 miles on them at most. gonna do no more than 10,000 miles a year

 

Mileage doesn't mean a thing when rubber starts to deteriorate. I advise against using them, but you can do whatever you want. I hope you don't experience any problems.

 

Here's what will happen. Tires will feel fine, plenty of grip, right up until you go into an unknown corner a little too hot and lift. WHOA !!! back end breaks WAY WAY OUT !! Tires get hard and lose their grip.

GET the new ones. Unless you have really good insurance.