Westerbeke caveats.
My experience with Westerbeke dates from about the age of yours, so this might actually help.The motor is essentially a British Perkins diesel, which is bulletproof (taxis in London, for example). Westerbeke Americanised and marine-ised it. The basic parts should be available or able to be shipped anywhere in the world, because Perkins has been used everywhere in the world.But beware all the ancillary Westerbeke things like brackets. At Cherubini we had nothing but problems with the alternator bracket when we tried fitting a 100-ah unit. It was cheap mild steel and could barely hold its own weight. On one occasion it broke catastrophically, causing major damage and threatening a grounding with no power. I think the water pump and starter are also non-Perkins.They are also apparently a b*tch to keep primed. Lose the prime and you are in trouble. I would recommend parallel Racor filters on fuel lines; be able to switch over to one under pressure to maintain the other without losing prime.They tend to hand-crank (well, foot-crank) easily, even the bigger ones... and this should suggest you might have to do it. I think the Yanmar was easier to do this but as I recall harder to hold the compression-release off when you kicked it... maybe I remember that backwards.Check the compression with a meter and look out for white smoke, blue smoke, knocks as with any other engine. If it checks out it should be okay. My impression is that for a Perkins diesel 3000 hours might be half-life. At Cherubini the installed Hobbes hourmeters had four digits and we had owners who reported theirs had flopped over. Properly maintained and responsibilty used it should take you anywhere and nearly forever.Good luck.JC