I was thinking the same thing. "Rust Free" is an unreal expectation.
On cars this old the only way you will get truly rust free is if the thing has had a recent and complete strip down and refinish, including metal restoration.
Hell, my car has 62,000 original miles and I know for a fact that it has been stored inside for the last 33 years (I know this because I drooled over it when I was a kid).
But you know...... It has a dime sized rust spot way down on the lower 1/4 behind the drivers side rear wheel.
So I guess my car wouldn't qualify.