Where to begin...
On my '85 the chain plates come up through the deck next to the cabin. If the '84 is like that and has the "U" bolts coming through the deck, I would look at those closely to see if they are pulling up and for any cracks. Also check the shroud turnbuckles while you're there for cracks in the swage fittings. I think the original turnbuckles were the Navtec style with dual turnbuckles and a screw/bolt connecting the two. At some point Navtec replaced the original stainless screw with a bronze screw, to prevent galling I believe. Check the swage fittings on the backstay as well.
Behind the seat back cushions in the saloon are several inspection port covers that can be removed to check the chainplate to hull connection. If the zippers in the headliner under the side decks still work you could open those and maybe get a look at the chainplate connection under the deck and a couple of the stanchion bases. Also check the bolts and plates that you'll find on the port side bulkhead between the saloon and head for signs of water intrusion and rot.
You might also check for any signs of leaking around the portlights, but that may not be unusual in a boat of that age. Mine gets a small drip now and then from the front/starboard fixed port.
Check the condition of the shaft coupling/stuffing box/pedro hose and the back of the transmission. If the stuffing box has been dripping too much and the shaft has been slinging water around the shaft coupling may be rusted solid. Mine was and the pedro hose plys (plies?) were starting to separate and leak. (It may be hard to get in there if there is a water heater installed.) If you are able to, also take a look at the heat exchanger for signs of leaking at the end cap and the condition of the hoses and connections. If that H/E is like mine there is only one end cap and it is on the starboard end of the H/E.
Check the bilge for water and the condition of the keel bolts. There are two access hatches in the main cabin sole where you can see some of the keel bolts. There might be some surface rust, but I don't think they should be "caked up", at least not if the bilge has been kept relatively dry. There might also be a panel in the floor inside the locker under the aft-facing seat at the dinette table that can be removed to check the bilge at that point. There is at least one keel bolt that can be seen in there. If there is a lot of water in the bilge you have to wonder where that is coming from.
Check the winches to see if they turn freely and for excessive play. If they are clean and well lubricated you should be able to turn them easily with one hand just by grabbing the top and rotating with your fingers. If they are hard to turn they probably just need to be disassembled and cleaned. Grab the big winches with both hands and try to rock them back and forth; if there is a lot of play the bearings/shaft is getting worn. Not much you can do about that short of replacing, but one of my winches has a fair amount of play and it still works well.
Check as many of the through hull fittings as you can get to. They may have gate valves, which are not good and should be replaced. If they have bronze or Marelon ball valves check to see if they open and close freely. My boat has the Marelon valves and if they are not exercised occasionally they can become stiff and hard to turn. They should be lubricated occasionally as well. True seacocks mounted to backing plates on the hull are best, but I don't think any of these boats included them originally.
There are plenty of things to check. These are just a few that I have learned about having owned this boat. At some point, if you are seriously considering the boat, you'll want a good marine surveyor to take a look.
That link to the Sailnet article is good!
