About that sludge. . . I believe the guys at La Jolla Independent, who have photos similar to these, when they say that the engine was driven by the proverbial old lady---hey, that's pretty much a given in La Jolla, where I am considered a young man by my doctor---and serviced by the book. I surmise that a lot of sludge comes from condensation from an engine that is never fully heated up by short drives to the salon. . . . Or, hell, maybe they used roofing tar instead of Castrol synthetic!