A member of the German Pagodentreff.de group is reproducing the the paint plate (all models - available now) and the VIN plate (230SL/early 250SL - available in about 6 weeks) in the engine bay.
If yours is damaged or lost here is a chance to get a new one made - he just needs to know the numbers and how many lines your body and paint plate has.
http://www.pagodentreff.de/diskussionsforum/showthread.php?p=68293#post68293 Euro 75 for one or two plates.