OK folks, I bought an empty FOB on ebay. This FOB is a direct match for our car. Lock, Unlock and Panic with the red window for the LED. I followed the instructions above and I now have a new looking key. I reused the key blade and all the guts. It was not easy to get the old FOB apart but with a little patients and nervous sweat, I got it apart. I did not glue the new FOB together - just snapped it. I told the guy to add the Crossfire to his list of compatible vehicles but I'm not sure if my email translated to Chinese. Do a ebay search on the below:

98-04 MERCEDES-BENZ SLK-CLASS FLIP KEY KEYLESS REMOTE FOB CASE FREE INSTRUCTION