I am a new member and an old tire guy.
I would not run the older tires on the steering position, but on the rear they would be fine, as long as it's not a heavy hauling vehicle.
All that said, I would really consider replacing them.
But, if you have your heart set on them, I would take them to a retreader and see if they will buff a bit of the tread off. Alternately you could try it yourself with a belt sander.
Hopefully you have better things to do with your time though. And do consider your safety.
