Mileage is unknown but low. I would say less than 5000 miles. The I only put 2500 miles on the car during the 7 years I owned it and they were on the car the whole time. Previous owner installed them right before I bought it. I recently sold the car, but held on to the rockers and valve covers.
I'm working on a possible trade with the covers and the rockers for some much needed parts...