I have a 66' Mustang that when tires were new could take left turns at 35+ miles an hour and only chirped when hitting the tape stripe at crosswalk (modified suspension).
After 10 years of VERY low miles and ALWAYS garaged the tires LOOKED perfect but had the traction capabilities of wet ice. I would still take it out and do some safe panic stops to test. Can't hurt. Just sayin'.
Candy Blue SE HB, 6sp Auto, Sport Package for the wife
Sterling Metallic SE HB, 5sp manual, Sport Package for me