I'll repeat my previous questions:What is the mileage on the engine? Do you see any smoke from the exhaust at any time. Do the plug electrodes actually get fouled or is the insulator just getting spotted? Sometimes you will see weird types of plug fouling due to use of certain type of gasoline . How is the car accelerating? Do you see any evidence of blowby in the air cleaner housing? When you looked at the cylinder walls, were any of them scored, was there much of a ridge at the top of the cylinder?? BTW, when you checked the compression, did the tech assess the leakdown rate?? Also, which W124 do you have and what year is it? If you are really convinced that the oil control rings are your problem, then try what Steve suggested. We'll try and get some of your horses back. How's the fuel economy also?? I've got the time if you've got the patience to wade thru this inquisition.
1987 BMW 325