Re: survey moisture readings
Cannot give you an indication of how serious the moisture is without knowing the extent and location of the high readings.
But, generally speaking, . . .
I assume the readings are from a marine moisture meter, like the Tramax Skipper Plus. A 20% reading would indicate a fairly high moisture content in the fiberglass. So, presumably any wood that is encapsulated by the fiberglass would be wet.
High moisture is one the first stages of the rotting process for wood. With a 40 year old boat, it would warrant further investigation as to the extent of rot, etc., since it has had plenty of time.
Considering that the readings were done 2 years ago, it may be worth doing some current readings and maybe drilling some test holes in parts of the structure.
