My response was a cheap last ditch effort. Honestly, I couldn't know how your engine will respond to the oil. Am I retreating from what I posted? No.
Sooner or later, you are going to at least have to do your valve stem seals.
My suggestion was a cheap long shot. Adding the high-mileage oil to our 300e did reduce oil consumption..... but it is not fouling plugs.
This is what I see: If you have the time window, give it a try. If time is critical and you simply can't wait and have to solve it ASAP .... pull the valve cover and go for the seals.
Hopefully this will help clarify ....
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)