Just found an analysis in my files from a friends '84 300D, from 2004. 150,000 on the car, 2350 on the sample. Penzoil Long Life 15W40, mostly short trips around town.
Iron was 10ppm and lead was 1ppm. Chromium was 0, copper was 2. Si was 7ppm.
FWIW...just another data point.