I ordered a complete (supposedly OE) Bosch system from ******** for my '72 350SL.

The distr cap and rotor are OE type.

The wires are Bosch Premium (Opt-Layer Mag) and plugs are Bosch resistor type. The wires do not have resistors built in and are not copper. Box is contradictory in that it says wires are stainless steel spiral wound for American and Asian cars only but also says they are for Mercedes V-8 engines!

Original '72 vintage wires had resistors built in to end fittings - 6kohms at one end and 1.6 kohms at other and presumably copper wire between. Plugs were non-resistor type.

Total resistance of original system was about 8 kohms. New wires are 1.6 kohms and with plugs may be about same as originals. I wonder if it makes any difference what wires we use, so long as overall resistance of circuit from coil to plug tip stays approximately the same??

I went ahead and installed the new parts. All I can say, is that the car is running well and that it does not miss from idle up to max revs. No interference on radio. One experienced MB technician says my set up is fine and he has been working on MBs all his life.

I still have original blue coil. I have been thinking about switching to Pertronix point-less ignition (Ignitor). They sell a coil that goes with their system for about $40.00. have not determined yet if this would be suitable for our car. But, you should be able to get an OE equivalent coil from any of the on-line vendors.