Do you know what clearance the machinist honed to between the pistons and new sleeves? The OM617.952 engine in my 1985 300D failed at 330K mi, so consistent with this experience. 3 pistons had broken ring glands, but I don't recall broken rings like this engine shows, but has been ~10 years. My #1 piston had depressions in the top, like a small ball-bearing was bouncing around, and left similar marks in the pre-chamber and head. I have no idea what. I later rebuilt that turbo and the compressor wheel looked fine.
I put new cylinder sleeves in all bores. I kind of lucked out since I recall paying only $11 ea, and saw them much more today. Couldn't get new pistons affordably (>$500 ea if you can find), but you (Rollguy) sold me a set of used ones. I haven't taken the block to a shop to deck the sleeves and hone to the pistons (hence my question). I found a used engine in like-new condition (>400 psig all) for $350 plus access like starter, alternator, vac pump and been running on that since.