You seem to be saying to have done a lot of these. Are you a MB mechanic or just a private restorer. I know from my extensive gas engine experience that many pistons are scuffed. Also, I am concerned about ring groove wear. Is it your experience that these are not usually issues with these engines. I was hoping, if I coudn't sell it and ended up rebulding the engine, that I could get away with new sleeves and the old pistons. Is that usually the course you take?