Decks yes, tanks no, though the tops needed rust treatment.
You may find the material in the real deck sandwich under the decorative teak is not wood but foam. As early as 1981. I got a glimpse of mine around the cockpit lazarette, and it was. But a 1979 boat had teak offcut blocks.
I would still class the fix as bad, ie expensive, getting towards 30KAUD. But I replaced teak with teak, except fwd at the bow section.
If you search old threads you should find plenty of information. Disquieting, but still information.
My fuel and water tanks were still serviceable at 39 years old. Pretty good.
2005 Integrity 386 "Sojourn"