Hattie, car has service records. It was changed at the MB dealer, according to the FSS, so about every 17,000 Km or so. I don't know if they used synthetic or not. They would have used whatever was recommended at the time I would guess.
When I started it today, it was fine. No smoke at all - completely clear. It seems like it only smokes after the car has been sitting for at least two days without driving.
So I'm hoping it is minor at this point, either valve stem seals or perhaps minor sludge buildup. If the rings were sticking badly, I'd expect to see higher consumption and/or more smoke while driving?
Musikmann - lol, driving hard isn't a problem for me. She gets a good workout most of the time. I didn't buy this car with an upgraded suspension just for tooting around the neighbourhood!
Thank you for the feedback though!