I never understood Mercedes thinking when it came to wipers.
W114/115: dual arm, pivoting at outer edges of windshield, leaving "rearview mirrow area" unwiped.
W116, R107, W126: dual arm, one arm follows the other to a "V" shape
W123: dual arm, similar to what you see on 99% of cars today
early W201: single arm, non articulated, with a "mini wiper" blade at the bottom
W124, W201, W202, W210, W208, R129: single arm, articulated
W140: dual arm, articulated on driver's side.
R170, A163: dual arm, same as W123.
W220, W203, R230, W211: dual arm, same concept as W123 but with a eccentric pivot on the passenger side arm.