BillyR,
I'm gonna go out on a limb and make a couple of assumptions.
Our boat's a 1985 Vagabond 39, so I'll share with you the major things I've discovered over the winter as I've been doing a major refit -- a project that will take far longer than I initially anticipated (even after adding an additional 1/3 to my time estimate.) Some of my headaches are related to PO "upgrades," after-market add-ons, and "out of sight, out of mind" negligence so take that into account.
The builder of our boat was Bluewater Yacht Builders in Taiwan. Hull ID should start with BYB.
The hull construction is solid FRP (polyester.) Now dealing with prevalent blistering between the mat and first layer of roving (a PO barrier coated, but likely over a wet hull.) Full keel with encapsulated ballast. Very sturdy. Through-hulls and seacocks are bronze. Backing plates for the seacocks are plywood covered with one layer of glass, but I've got several that needed replacement due to delamination. They were not impregnated with resin before they were bedded to the interior of the hull and then glassed over (before they were drilled for the TH's.)
Deck-hull joint is through bolted. I've found no separations or leakage. Bulwarks are very sturdy, and are topped with a wide teak caprail.
Teak decks came standard, although most of ours were removed previously. We've founds several areas of existing leakage, as well as prior repairs. Something to check closely.
Standing rigging is hefty, but not 316 stainless. Bobstay in stainless rod, attached to the hull right above the waterline. Chainplates run down through the teap caprails, through-bolted to the hull, and are internal. They are NOT easily accessible for inspection. Getting to them will require removal of cabinetry. A clear negative. Our spars are Isomat; not exactly easy to get spares. RigRite seems to be the only game in town. Deck stepped mast with a stainless compression post.
Interior fitting has been a pleasant surprise, but seems pretty comparable to it's Taiwanese cousins (Tayana/Young Sun/Ta Shing/Passport/etc.) The teak ceilings are not veneer, but real battens laminated to plywood bulkheads. Ditto for the teak/holly sole. Very rich, warm and inviting.
Headliners are molded FRP, held up by teak trim. Very convenient to drop a panel and access wiring/deck fittings.
Tankage is a good news/bad news story. Potable water and black water are monel (Yea!) Fuel tanks (dual port and starboard) are black iron sheathed in FRP (Doh!...) All tanks have decent inspections plates installed, but tank level sensors are not standard.
Wiring is is not as bad as it could be. Copper stranded, but not tinned. Connectors are vanilla crimped terminals -- heat-shrink connectors are are all post production. Decent breaker panels and wiring runs.
Through-deck penetrations were not potted. We've been adressing these as we re-bed hardware.
Standard winches were Barient -- no longer in business. No a major issue, but something to consider. Easy to clean and service, but spares are not really easy to lay your hands on. I'm told Lewmar pawls will fit, but luckily I've not had to test that.
Our engine is a Perkins 4.108M. Moves us quite well with a reasonable fuel consumption rate.
Lot's more info if you want it -- I'm happy to share. PM with questions.