Great boat, have had ours for 15 years, and don't plan on parting with it anytime soon. Nothing too ugly, but on a 35 year old boat, lots of little bad things will always pop up. Fortunately, many parts are still available, and accessibility in general is excellent.
A couple of water damage related things: check for signs of water damage around the fuel tanks, especially the forward ones (1"x1" wood bracing at bottom). At least on ours, a 1980 model, they filled in behind and in between the tanks with foam which gives the water no place to go. Had to replace the forward port tank a couple of years ago. Also look for water damage on the laminated plywood under windows and doors in salon. Feel around with your fingers, laminate can look good, but the plywood behind might be rotten. If it's the boat I think it is, it's the same almond laminate color we have, still available! Check the port locker in the companionway to the aft cabin and the port hanging locker in the aft cabin as well for water intrusion. Also the two small compartments on the rear wall of the aft stateroom on either side of the bed.
Had the Onan 7.5 KW originally, replaced it with a Northern lights almost a decade ago, highly recommended.
I'm sure the surveyor will have much more to say!....
Good luck and do keep us posted!
Rick