If you are concerned with longevity, go with :
Timevalve Manufacturing - Stainless Steel Exhaust Systems and Catalytic Converters for Mercedes Benz, Vintage Ferrari, and other Classic Cars
They make Stainless Steel exhaust systems.
I think when I replaced the exhaust on the 85 300D several years ago, I used Ansa.
Was a straight bolt on w/o any problems. I replaced everything from Down pipe back.
As mentioned, with a Diesel engine it will last a long time compared to a gasser.
The Mufflers for the Diesels are a straight through design, so no baffles to create back pressure.
If I were to eliminate one, it would be the center Muffler.
Charlie
sent from my pos computer