Thank you again for that info. I think at this point, whatever part it is causing the problem it sounds like I'm in for a whole new clutch kit - like I mentioned over 100k miles on the car and for all I know, still on the original clutch. This is the most simple "Occam's Razor" explanation for why it may have given up. It's just a matter of finding one to suit, which is proving to be a challenge! Any clue whether it uses the same clutch parts as the 2003 SLK you mentioned, or is that hoping a bit too much?