I am looking into buying this boat. BUT, the one thing that is holding me back from pulling the trigger is the owner states that the gas tank needs to be replaced. I have not spoken to the owner in regards to the details as to how it was determined that the gas tank needed to be replaced. As per Four Winns for this model and year it is a 75 gal tank. I want to get some input and approach this as a "worst case scenario" deal. The boat does not have a deck access to lift up a cover and reveal the tank to inspect. Please advise.