Dead Pedal isn't actually a M-B part. It is a "look-alike" that is of reasonable quality. You can do a search on eBay or Amazon (where I purchased) using the following:

Stainless Steel Footrest Foot Rest Dead Pedal Pad Cover For Mercedes Benz A B C E S CLS SLK CLA GLA GLK ML G GL Series

Dead Pedal is somewhat universal across M-B product lines. Cost me $20. I used industrial strength, double-sided tape to hold it in place. Worked fine; never had the dead pedal come loose.

Happy Hunting