Yes they are interchangable, as the ET is the same.
Malcolm
The ET might be the same but the 210 wheel bolt is of a smaller diameter than the 211, also the 211 I belive has a shorter shank, so I would double check with MB parts dept first before buying any.
Sorry Malc, don't what to tread on anyone toes!!
I am running W211 wheels on my W124. W211's have 14mm bolts, W124 12mm. As long as the cups on the bolts seat into the holes there is no issue running 12mm bolts in them. A Merc dealership will frown at such a "fix". However as long as the seating is good there is no issue and is as safe as.
The ET is always the big issue!!!
Greg