I am in the middle of changing valve cover gaskets on my 2000 C280, M112 engine. On the valve covers there is a smaller gasket to the air chambers that look pretty worn and it may actually just be a bead of sealant I have not taken this apart because I don't have the replacement part. What are these gaskets called? I don't see them mentioned in any of the online parts catalogs.

The dealer sent me a picture of the parts in this area and there doesn't appear to be any gasket called for. I guess then that just some sort of sealant is called for?