I think I found it, apparently the same kit I used on my vw may be used. My wife has the car right now but does anyone know off hand if the hazard switch blinks when engaged? If it does the kit should work. I will attach links I found.

HOW TO: Retrofitting tap to pass turn signals to your W123 / W124 / W126 - PeachParts Mercedes ShopForum

I know it says w123 etc,but if our hazard switches blink it should drop in.

Tim