Welcome to the forum. At 21k miles that thing is barely broken in but a 1980 should have a lot more miles on it than that. Has it been ridden regularly? If not you really don't know what to expect next. My 2013 Vision already has 16k miles on it so I need never question if it has been on the road much. For your bike keep a close eye on it. It may be just fine if the prior owner took good care of it but it is in a place that would make me nervous.