Hi Gordon and welcome,
These are lovely boats to cruise in, comfortable and better performers than the later Mody 40 and 42 although her slightly bigger successor, the Moody 44, will outperform the 425. However, like all boats, they have their issues. For boats of this age, her condition and hence value, has more to do with how well she has been looked after than how well she was built, but the basic layup is sound and, by modern standards fairly heavy.
The teak on the cockpit sole and seats was originally teak faced ply and in most cases has, by now, been replaced by solid teak or one of the better teak substitutes.
The furlers (main and genoa) need annual lubrication and a thorough overhaul (strip down, check, replace worn parts) every 10 years or so to keep operating smoothly = when were these last done?
The steering gear is a Whitlock Constellation cable system which should be delightfully light. The conduits for the cables get worn by the cables themselves.Wear is much more rapid if the cables are too tight, so it's hard to give a lifetime. Many boats have replaced cables and conduits by now - the original conduits were red and newer ones, since some time before 2010, are blue.
In common with all Moodys of this era, all 6 chainplates pass through the slde decks and are secured to the hull by bolting to a marine ply part bulkhead down below. Each deck penetrations is sealed by a sealant covered with a small stainless plate screwed to the deck. Over the years, this sealant dries out and cracks leading to leaks which can wet the part bulkhead below, but this can escape notice because down below, all is hidden behind beautiful cabinets and bookshelves. If this goes on for long enough, the Marine ply can rot and get soggy which ultimately allow the bolts to tear through the ply. In ne case, last year on a Moody 376, this resulted in dismasting. Prevention is simple - rebed the little sealing plates with a modern sealant every 5 - 10 years and, if you like re-assurance, arrange inspection ways through the cabinets to check the condition of the part bulkheads (knees). A useful check is to put a straight edge (steel rule) on the deck around the chainplates, if you detect any bulges in the deck, it warrants further investigation.
Hope this helps and happy hunting.
Peter.