Several engines used dual point distributors ( M100 V8 and several sixes).

The points on the transistor ignitions (blue coil) must NEVER be cleaned with a file or anything abrasive, they are platinum plated and will die quickly if abrasively cleaned. They are a logic switch only, they do not operate the coil if the transistor box is working.

There is no gap spec for MB, they are set by measuring the dwell.

Benz started using the transistor switched system around 1970 (possibly earlier), and changed over to a breakerless (Hall effect trigger) sometime in the late 70s. Very positive change as far as I'm concerned, since the timing no moger varies with rubbing block wear.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!