Thanks Sixto for your reply!
my 1984 190d doesn't have the hydraulic engine mounts, just the solid rubber ones and they have been replaced last year. Thanks though for including the diagram.

The vibration of the lower idle at stops isn't as much of a concern to me as the lower idle speed itself. Before tightening up the throttle cable, it stalled at least once at a stop. It is better now, but still feels iffy.

I will take a look at my repair manual to learn about adjusting the IP's idle and the presence/ location of a solenoid to regulate idle, unless you have a reference...

What is EDS?

Thanks!