It looks as if there was a happy outcome to this issue but wanted to relay the following: when I bought my used MB, I had the party I bought it from take it to a near by MB dealer’s shop to do the equivalent of a Starmark inspection. This is a 130 point review of the car used to decide whether to permit a factory extended warranty. From previous experience, I found that in this inspection they do not look underneath the valve cover, nor underneath the battery. I paid a small extra amount to have them do this as well as a few other extra things, as I wanted to know the condition of the top of the valve train.
Still they didn’t check the timing chain or tensioners. That was okay with me as the car had a mere 60K miles on it. The moral of the story is that if you want even a MB dealer to check for specific items, you have to expressly tell them to do so. It kind of sucks but on the other hand it’s difficult to second guess where an inspection starts and stops. For $150 or so they are not going to spend all that much time….
Hope you continue enjoy your fine new toy none the less!