Here are the parts I would change.

L3000-24957 Strut Assembly Comfort Bilstein IN STOCK $109.81
http://catalog.eautopartscatalog.com/mercedesshop/sophio/quote.jsp?clientid=catalog.mercedesshop&cookieid=20M0MUBJF20M0NEB0Z&baseurl=http://catalog.peachparts.com/&partner=mercedesshop&year=1987&product=L3000-269263&application=000046523

Bilstein standard rear shocks should be fine, unless you carry heavy loads.
http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=20M0MUBJF20M0NEB0Z&year=1987&make=MB&model=300-DT-002&category=L&part=Shock+Absorber

PART NUMBER SEARCH RESULTS WITH PRICES
Vehicle 1987 Mercedes Benz 300D Turbo
Part: Sway Bar Link
Note: Rear
From rear sway bar to trailing arm.
L1030-16352 Sway Bar Link Febi IN STOCK $10.29
http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=20M0MUBJF20M0NEB0Z&year=1987&make=MB&model=300-DT-002&category=L&part=Sway+Bar+Link


You need professional MB tech inspection of the Subframe Mounts Left/Right rear Thrust Arm bushings, Control Arm Strut , Rear Control Arm Stay Left/Right, Front Lower Control Arm Bushings, Rear Lower Control Arm bushings, Camber Strut Left/Right Upper rear position, Ball Lower Joints left & right, Tie Rod Assembly's, Idler Arm, Steering Coupling, Power Steering Filter...





W210 Spring Perch Failure - Please read.
http://www.peachparts.com/shopforum/showthread.php?p=638651


Suspension:
http://www.peachparts.com/shopforum/showthread.php?t=142397