"recommends replace of steel water tank that is not leaking to a plas. tank,"
Sounds like typical surveyor BS. If there's no problem with the steel tank, why put it on the survey?
A\ friend had his boat surveyed and the lady surveyor put all kinds of goofy recommendations in but only a few requirements. The insurance company told my buddy to do all recommendations AND requirements or he'd be limited to in-water port coverage. One of the recommendations was to install nav lights that comply with the modern standard. But the CFR is explicit in grandfathering in lights on classic boats built before the modern standard went into effect. It took a week of negotiation with the lady surveyor, including sending her the reference in the CFR, before she finally agreed to strike that one recommendation from the survey.