Perhaps you are right. It just seems that many would rebuilt or do repairs to an engine well before this point. My barometer for engine rebuild seems to be more based on compression and evenness of compression in the cylinders, that is power and smoothness. I do not burn or use any oil between the changes in this w113, but I am not using that to mean that my engine is in perfect health in any way, I know better. But I am more used to Italian and British engines, I remember one Giulietta Veloce engine that I had rebuilt by the best source I could find and it certainly used the oil right from the beginning. They just did.
I just think it's very interesting that MBZ quote this high figure.
-CD-
1967 230SL, 113.042 10