Thanks both very much for the replies. Not sure how it was diagnosed. The part number off the unit is (not sure where all the spaces go) 006 545 76 32. When I called the local Mercedes parts dept. they gave me 008 545 62 32 as the new OEM part number based on the VIN of my car.
So, it looks like I can use ANY ignition module from ANY 300E 6 cylinder gas car. BUT, question remains, do I need to buy a new coil as well?

Thanks for the replies, looking forward to getting this thing fixed in the next week or so.

Regards,
Tom in Tulsa