Here are some photos of the cowl in its current terrible state. I also took pictures of the newly installed wiper and the old part. The parts ordered by the dealer are the 2 strips pictured in my first post. I think, too, that the dealer ordered the wrong parts.

It seems like the trim rings around the clamshell is also another difference (one plastic and one rubber), but comparing the two parts, it appears that both the rubber one on the replacement part and the plastic part on the old one can be changed out. The only other noticeable difference is that the later one has a clamshell top that snaps off without the need to take out the whole wiper and unscrew the clamshell screws from the bottom. So, it appears that maybe getting the correct one piece rubber molding (it appears there may be an additional rubber gasket (part #21 in the parts picture in my first post) that goes under the wiper) should hopefully work.

Attached Thumbnails

       

__________________
Brian
'94 E420 - 99K
'12 C300 4 Matic

Previously owned:
'06 CLK 500K Cabriolet
'85 300SD (Old Smokey)
2002 Boxster
2002 C320 (The five-pointed star Mercedes)
1993 300E 3.2 (Dealership's cash cow)
1979 300SD (Chrome beauty)
1983 300D (Old faithful)
1983 240D (Right lane cruiser)
1977 240D (Miracle of bondo)