Bob,
Wow - glad you are OK, and sorry to hear that your car is probably a mess now.
You are right, the Benz is one of best cars to survive an accident in. I flipped my first Benz (190D) over at freeway speeds in a freak winter accident, and also walked away. That convinced me to buy another (which I did... then another, and another, until it became a sickness!)
About the oil, you are 100% correct - MB only tests what is submitted to them. Mobil has not (yet) submitted Delvac-1 for testing. However, I believe Mobil has submitted all 5 versions of Mobil-1 and the three lightest weights did NOT pass their tests! Personally I don't like any oil with the "second" number less than 40, like 0W-30 or 10W-30. I don't see much if any benefit to using these water-thin oils, since the "thick" synthetics provide cold starting ability well below zero F. But all that aside, the most important thing is to make sure whatever oil you use is diesel rated (CH, CI, etc.) You'd be surprised how many oils are not diesel rated, look at the labels the next time you're at the local McParts!
Regards,