I say again, box up the head and send it to Greg Atwell, it will save you money and be absolutely as good as new.
It's really funny to hear from time to time people saying that a Benz is not made as good as it used to be. It's funny to me because I've been hearing this for the past 30 years, and the cars are getting better, not worse.
It really puzzles me to hear so many myths as they pertain to automobiles. Try a Chevy or Ford. You'll get 200,000 miles out of one if you take really good care of it and are lucky. When it comes engine time on most other cars besides a Benz, there's nothing left worth putting an engine into.
Occasionally, even a Benz will have a problem, but the difference with a Benz is that you can fix the problem and it will stay fixed, and you will have a solid car underneath you again.