Thanks for all that really useful information. It certainly has given me a bit more confidence in proceeding down the path I'm going.
Coolrunnings, one of the things that drew me to the cavalier was the active association. Unfortunately, they've finished racing for the season but I'll drop them a line and see if I can get a trip out with one of their members.
Cisco, I noticed that the majority of the boats I've kept my eye on have a Bukh engine, but I was under the impression that they were good little unit? Still, I'll be looking for one which has either had the engine or rigging done recently - I might be waiting a while if looking for both

Osmosis is always a concern but I've sailed on enough boats of this vintage, and older to know that example which have been looked after make great yachts.
Thanks again.