They all rattle at the damper/bolt location

Do as ILUV suggest.
The place is where bolt#6 goes through Damper #10.
Best time to catch it is at idle, in gear ,w/foot on brake.. have someone do that while you jam a screwdriver in there and you will hear it stop as soon as you apply pressue...
Very Common.http://webwench.net/w123manuals/Service/W124/w124CD1/Program/Engine/103/13-3450.pdf

There is an easy O ring fix in the Archieves...