While changing out a skewer for my Bob trailer, the mechanic asked when I went to the beach.
He could tell I'd been there by the condition of my 94 steel frame even though it was just for a week.
He felt the frame was still ok for a 1,000 mile trip, but he wouldn't take it cross-country.
If the bike in question has had exposure to salt, I'd be reluctant to spend more money on it.