Thanks for your answers. Comodave, if the survey shows anything wrong with the deck, or rather the underlying wooden core, I'm simply not buying the boat. I don't have the gut, patience and finance to rip off a deck and replace with something else. Plus, on a GB, I think the look of the deck is important to its appeal, I'm fine with a GRP deck on a recent boat, but not on this.
Slowmo, I was in fact looking for Lehman engines, even though I understand that Cat parts are easier to get a hold of here in Europe than the FL. I did check the window tracks, they look good, some seals may benefit from a replacement, I may replace them all for peace of mind. It's not raining often where I live, however when it does rain, it's pouring heavily, or even dangerously.
I know teak deck and 30-year old boat mean high maintenance. I'm lucky to live 15 min away from the dock, we shall see how much is too much ! ;-)