I don't think that's an SL500, but who's counting.
Unless it's supercharged for 2004, Kompressor means it would be SC'ed.
The SL500 is just the 302hp 5.0L V8. Unless those pictures came from Germany, they have a Kompressor SC'ed V8 over there.
EDIT: Can't seem to spell Kompressor right in my present state of mind.