Fastlane has both the bosch wiper blade insert (the rubber part) and the whole blade assembly (looks like, at least, no picture). At least for my 300E, the blade insert does not come with the metal spring pieces, so you'll need those if you want to use the oem insert (if you don't still have them, then either get the trico-made MB inserts from the dealer, which don't need them, or an aftermarket from a mcparts store).

Sometimes wiping old blades with a clean tissue, moistened with rubbing alcohol, may help restore performance.