Hi Bob, saw you posting about osmosis. I'm no expert on the subject but from talking to lot of people in the trade here are my observations for what there worth.
Most boats of this era can suffer to a varying degree with osmosis. Many factors affect a hulls vulnerability. Quality of materials used etc.
Check the history of the boat, has it been laid up ashore regularly. Opinion is that drying out the hull can prevent onset. I currently have a P32 built 1980 one of the last ones. Its been in fresh water all its life (I'm told that fresh water stimulates osmosis more than salt) but is always brought ashore for the winter. The hull is clear as a bell, I know this for sure as I've stripped her back to the fibre glass. Once cleaned and dried out (get it tested professionally) I coated her with GEL PROTECT. If you find a boat with this applied ask if its been put on for prevention or curative. I recon the safest bet is if your serious about buying is to have a survey, it could save you £s or should I say $s. The only other thing I recommend is to have a good look at the legs. I've had some minor problems but they can cost serious amounts of doe to put right if neglected so check the state of gaiters and hoses. Hope this of some help
Regards Mikey