Sounds like you need a new door check strap unit.

http://catalog.worldpac.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=2E60GA1KL2EB0OM96C&year=1981&make=MB&model=300-SD-002&category=O&part=Door+Check

I think I read that someone (maybe Kerry?) took his out of the door and was able to repair it. But they are pretty cheap for a new one.

__________________
Chad
2006 Nissan Pathfinder LE
1998 Acura 3.0 CL
OBK#44
"Pleasure in the job puts perfection in the work." - Aristotle (384-322 B.C.)

SOLD
1985 300TD - Red Dragon
1986 300SDL - Coda
1991 - 300TE
1995 - E320
1985 300CD - Gladys