Back in the late 60's a friend of mine had a 1966 VW. If he changed the oil and found one fleck of metal on his magnetic drain plug he would tear down the entire engine and do a rebuild.

I helped him twice. He could pull it, overhaul it, and replace it in four hours. But then he had everything necessary to do the job. He could even grind his own valves.

This experience came in handy years later when I needed to do a 914 1.8. It took me about 20 hours of labor, but it all worked when I hit the key!

I also once did a VW Vanagon water cooled which are known for blowing their head gaskets about every 30,000 miles. The water cooling made it a bit tricker, but it all worked when I was finished!