psfred... thanks. Today after my classes and appointment, I stopped by the Mercedes dealership and bought the oil cap. I didn't see a difference in ordering it online for less and pay shipping or just go the dealership. In any case, I might have spend a couple of bucks more at the dealership. When I went to replace the oil cap, I noticed today A LOT more oil around the filler area and it spreading back. I went ahead and replaced the cap. While I took the old one out, I examined the gasket. I didn't see anything wrong with it. It felt the same as the other one. However, when I took the new one off and put the old one back on... I felt a difference in how it sealed and the new one was WAY better.

BTW.. you are right.. the oil cap is the 111 model. Both the old and new are 111.

I will come back to this thread on my next oil change and post results.