I'm in the middle of replacing my cruise switch and I've one question: the bolt that holds the steering wheel on a 1988 300sel IS a standard right hand thread is it not? The reason I ask is, I just sheered off my 10mm allen type socket trying to loosen it with a braker bar, and I don't want to also end up messing up that flat bolt head.

Yes sir right hand. Usually very tight. I have had good results with impact tool removal of this item.