About engine blowby on e220 cdi pre facelift

Today I've been checking out e220 to buy and I took off oil cap and saw little but noticable smoke coming out. Is this normal for diesel engine? Or it's blowby? Engine didn't lack power and actually was well taken care of the way car was driving (280k km) Also does these cars have factory issue with body alignment or there's simply not a single one left that wasn't crashed?