You need to replace the part that attaches to the firewall. There is a nylon bushing inside which disintegrates after about 20 years. It is apparent in the first photo that the horizontal rod has moved too far forward, so that the linkages on the valve cover are overlapping. The two linkages just behind the STOP lever should be nearly an inch apart. The rod does not appear bent. It's just sagging at the firewall joint because the bushing has failed.

Here is what you need:
http://catalog.eautopartscatalog.com/mercedesshop/sophio/quote.jsp?clientid=catalog.mercedesshop&cookieid=1PY1E2LZD1SQ016Z8T&baseurl=http://catalog.peachparts.com/&partner=mercedesshop&year=1982&product=C7030-16051&application=000012097

Someone else reported the same problem yesterday. Since you have already suffered through a throttle failure, you might not be so inclined to try the bondo technique!!!
http://www.peachparts.com/shopforum/showthread.php?t=152540