When I bought my 1960 TR3 in 1993, it still had the original Michelin X's. The car had less than 23,000 miles at purchase. I drove it a few times, including the 70-80 mile trip home.
The side walls showed a little dry rot, but the tires were hard as a rock. I could really let the tail hang out in the bends. It was a ball to drive.
But, it was a relief to get new rubber.