Hello Harry,
Yes, some of these early MB cars used a separate grounding strap on the cables. I believe that these small ground straps help protect the dash instruments in the event main that chassis grounding is lost. They appear to be a redundant back-up system. I do know a list member who fried his engine temperature gauge. During dash repairs, he accidentally left a chassis ground wire loose. When he went to start the engine, the engine temperature gauge became the only conductor for ground current. The gauges small capillary tube could not handle the load and burnt in two!
