pass. side front

How can to be sure it's only 41k miles and not 141k or 241k miles.

I bought the car from thr original owner at an estate sale. Car has been in the garage since last registered in 1980. I also have all the recipts going back to the first oil change at dealership in 1973. Not many z's have survived without major restoration/repair on the east coast with 141,000 or 241,000 miles, trust me.