After buying my 1991 300e 3.0, I pledged to keep it through thick and thin. I have discovered I need a head gasket replaced, which will lead to new valve guides and such. I was quoted $1500 by a reputable private European auto mechanic (his name is Helmut, what else needs to be said!). I was told that this was typical and that the repair will give me another 100K of life. I have 185K now. Anyone with a similiar experience? Wondering if it's really worth keeping 'ol Mary Beth?