I also have been trying to track down suitable replacement wiper blade refills for my 1968 280SL. I have tried several options, including those available on Authentic Classics,
Mercedes-Benz and Bosch. I am the second owner of the car, which I purchased in 1994. The recommendations in this and other threads concerning replacement wiper blades and refills are for 12 inch blades and refills. My blades, which look original and have not been replaced sine I have owned the car, are 328 mm, or about 12 7/8 inches. I know the wiper blades currently offered by M-B are approximately 11 inches and black. One suggestion on another thread was M-B part number A0008241227. Those are about 12 inches, as are another suggestion on the same thread, Bosch H305. All of these replacements are much thinner than my original rubber blades, except for the Authentic Classic ones, which are very close in size to my originals, except they are 11 inches long.
I finally searched the Bosch website, using vehicle make, model and year. For a 1968 280SL, Bosch recommends Bosch DirectConnect 40513, which are 13 inches, so slightly long, but also narrow, requiring that the blade be pinched a bit so retain the rubber refill. I replace the metal strips which came with the Bosch wiper blades with my originals.
I have attached some pictures to illustrate the different blades.
After all this, my question is, are my Bosch 328 mm wiper blades original?