Il give Mercedes a ring see what they say, im not going to drive myself mad though, its at the age now where the last few years since the second owner had it it might have been in a specialist rather than main dealer.
Good luck with that. I'd be interested to see how you get on. My old CL500 which I got cheap was missing its service history and I figured it'd be like BMW - phone up and get a replacement service book with everything ever done at the main dealers. Not so with MB in my case and they were naff all help.