We have an '89 Wolfsy Weekender with a relatively new (<30K) 2.1 German engine.  I also have an '84 Westy with over 200K miles on the original engine.  We camp in the '84 Westy ALL the time.  We only "kick-about" in the '89 occasionally just for fun.

My wife an I have discussed the fate of the '84 Westy and would replace the engine in a heart beat if (when) it blows.  We are not interested in keeping the Wolfsy but If I sold it, we could only get about $2,500.  We would easily spend about $3,000 to replace the Westy engine if and when it kicks the bucket.  Does it make sense to pull the Wolfsy engine and then part the rest of it out.  It is a good running Wolfsy, but its parts are easily worth much more than the whole.