Do you have any further info on the TSB? I have the same problem you desribed but MB refused to repaint it under warranty. Now, the metal is rotting away.
The W210 has more room inside and more room in the trunk than the W124. It's very quiet and the controls are light. The W124 is far more solid and yes, I will take the W124 over W210 any time. My name is Lucky and I am a previous W124 owner.