Hopefully a full blown resto won't be necessary, but in the back of my mind is a little voice that keeps saying the bike is 30 years old, so while it may look nice in pictures, it'll probably be hiding a few nasties when I start looking a bit deeper.
I'm thinking that the chassis will be a bit scabby at best, and may have some rust that needs attention before becoming a structural issue. Ditto the tank - if it doesn't leak now it probably will start to if some form of preventative action isn't taken. (I prefer prevention to cure - cure usually involves a dark windy very wet breakdown

)
If its as good as described then I'll be a very happy bunny! I'm hoping that its a good un - I always prefer to buy from a forum/club like this as at least you know the owner cares about the bike!