Found this
http://www.benzworld.org/forums/attachments/w123-e-ce-d-cd-td/594697d1381176466-ignition-gurus-pull-m110-ignition.jpg
If the diagram is correct for your car, you have a reluctor type distributor trigger. This is basically a low voltage AC generator where ( generally ) the falling side of the sine wave triggers the ignition module.
With type of trigger, you can use a GM HEI 4 pin ignition module ( 1974 to 85 ish ) and a remote ignition coil ( same era, mostly on inline 4 and 6 engines, however GM went back to remote coils in the early 90's on distributor based engines so they might work also.)
A high quality GM module ( STANDARD MOTOR PRODUCTS LX301 ) is about $ 35 ( generic $ 10 ) , ignition coil ( STANDARD MOTOR PRODUCTS DR35 ) $ 13 ( generic $ 10 )
The GM module measures about 1" x 3" x 3/8". The GM module needs a heat sink so don't just mount it to the fender, the the MB aluminum box would be fine and would allow you to use factory wiring.
There are some issues to tend to, nothing major.
Find the spec for GM reluctor coil resistance and compare to MB of 450 / 750 ohms just to make sure MB isn't using a coil wildly different from GM.
Research what polarity the reluctor coil GM uses and compare to your car. This can be arrived by trial and error, measure ignition timing with the MB system, make the conversion without changing the distributor then recheck timing. If it is more than 3 or so degrees different, swap the reluctor wires at the module and check again. If the polarity is incorrect, the timing will be very far off. Turning the distributor to compensate will bring the timing back but the rotor phasing relative to the distributor cap will be off. This will allow spark to jump to the wrong plug wire as mechanical / vacuum advance comes into play.
The two ballast resistors must be bypassed, current limiting is taken care of in the GM module. If this is difficult, use terminal 15 in the MB box.
For wiring I'd use pin 15 on the MB box as it is already before the resistors, also run this pin to the positive side of the ignition coil. 31 would be the ground , 16 would go the negative side of the coil. Also connect the reluctor wires to the GM module.
The GM ignition coil has a spark plug type high voltage terminal so you might need to make a coil wire.
Loss of tachometer signal from pin 10 of the MB box might become an issue as the dash might not be able to deal with being triggered from the negative side of the ignition coil. This could be a show stopper if the signal is used for other purposes like fuel injection / trans shifting / HVAC. Simulating this signal would be possible if we knew details. ( a lab type oscilloscope would tell the tale )
Your distributor cap terminal spacing dictates how wide you can pull the plug gaps open before you get arcing under the cap. The larger the plug gap, the higher the voltage will climb, this stresses everything back to the ignition coil as electricity is trying to leak out.