All offers are contingent on successful sea trials and survey. A boat that old, a good survey would be worth its weight in peace of mind and replacement stringers.
If you have concerns, voice them and see how willing they are to move. I tell people "I don't like to haggle over the phone without seeing an item but not going to make the effort to look at it if they are so set on price regardless of what is found, so is it worth me coming to look at?"
Mat has been around and knows what is going on.