Douglas -- That is a good photo of the black plastic knob on the speedometer. I broke mine several years ago, and its been missing ever since.
Do you, or anyone else, know where to get a replacement black knob of the type you've captured in his photo?
I've tried ordering from MB, but received some goofy looking metal (dull aluminium or some such) knob with threads, which didn't fit/work at all.
Here's an additional / different question: Over time the center gauge cluster develops a film inside the glass. Any experience out there about this? What causes this filming? Is there anyway to stop it?
I find that filmy/greasy look inside the instrument cluster glass very distracting.