Agreed, I did a valve job around 270k on my 300SEL and the bores were still full of crosshatching. Dry compression test revealed between 160-170psi on all six after the valve job.
Total cost was about $650 only, including machine work with all 12 new valve springs and all 12 guides replaced.
Car just spent 70 miles going 75mph yesterday on the way to dinner... no issues.
