The issue, as I see it is what might happen if a tire fails? A set of tires is around $600 give or take. How much damage can a tire do that comes apart at 30 mph? I've seen tires nearly rip a quarter off, or destroy a front fender when they come apart. That would really suck on a pristine original or correctly restored or a nice show car.

So to borrow a phrase from Clint Eastwood, "Do you feel lucky, Punk?"
Is the cost of a set of tires worth the cost to repair the damage an old tire might cause if it should fail?

I took a set of 15 year old Michelin's off my coupe before I went on vacation. This was a car that saw regular highway speeds and hours of driving at a time before vacation. I figured all the advantages of a set of new tires was worth the expense before departing on my vacation, and I would be able to choose what tires I wanted to buy. That option might not exist a couple hundred miles from home.

I don't have an issue with tires that still looked good that were 7 or 8 years old, but even my 15 year old Michelin's were starting to make me nervous. BF Goodrich tires sucked when they were new (I worked in a tire shop back then). One other thing I was a bit concerned about was, how old were the "new" tires I was getting put on? Seems there should be some kind of law prohibiting a tire company from selling 4 year old new tires, but there isn't. Where I bought my new tires, they had the date codes for all 4 written on the bill, I'm not sure if everyone does that or not. Gene