Six months ago I had the valve stem seals replaced and timing chain replaced on my'86 560SL due to excess oil usage. For a cost of $1400. It seemed to have solved the problem for a few months. The oil useage came back. Yesterday I picked up the car after spending $2500 for a full valve job . It seemed the valve guides were worn on a few cylinders. The car has 124,000 miles on it. It runs great more power than ever before. My advice do a valve job rather then the seals for now. Eventually it will need the valve job. Save your money and go for the full job(my humble opinion).
Larry '86 560 SL