Cliff,
My 190 has a Ford 302 stroked to 342" in it hence the use of the T5 Tremec tranny. As I said previously the bellhousing is the ticklish part of the conversion but if a unusable AT could be had that would bolt up it could be cut behind the convertor so that crank centerline could be logged. If a tranny from say an old 450SL would bolt to a E430 motor then it could be used for getting the dimensions but who knows if the patterns are consistent and what years would apply?
Only other quirk may be a manual pedal assembly but the assembly from an SLK or a Euro manual 210 chassis may fit. MB probably makes a non-USA 210/2.0L/manual...taxis!

Tobias MB
4 MBs

PS: If you go to Richmondgear.com you can see the gear charts for their trannys, choose the final gear you desire (5th or 6th)
and back up from there.