You would have to split the deck to replace the stringers right. If there was standing water than the stringers are bad and so are the bulheads. You don't want to have to split the deck $5,000 pluse $20,000 and your labor will float this thing again. The problem is someone will buy it, clean and paint it, replace the running gear with minimal concern and sell it to someone for top dollar and have that person learn fast the hard way.