The trims along the roof are clamped by replaceable clips (do not have the part# for those at hand). The part of the trims that is besides the front window is clamped by iron clips (but these never break).
The trim at the top of the windscreen is clamped by iron clips as well (but these break neither).
If you go to a MB shop, they should have these roof clips in stock. There are two different versions. The clips are white with either a red or a green part to tighten the clips. You probably need the green version...
with a minor 600+k