Is 60 years old too old for a person?
That's basically what you're asking.
All that is, is a number. It doesn't say how it was driven, how it was maintained, what kind of servicing was done, or anything else.
THE ONLY THING an odometer tells you is the total miles driven. It is 100% pointless to assume that it tells you anything else.
I have a 307,000 mile car that runs better than my dad's 60,000 mile car.
Because it's better maintained.
So ignore miles. Figure out what shape it's in, and make your own decision.