Don't take it from me, I know just enough to be dangerous most of the time, but I did replace my Shut Off Valve (SVO) on my 1991 300d. It really wasn't that bad, replacing it. Looking at it, and trying to figure out what to do, even after reading previous posts, was the hard part. Once I got to it, it wasn't that bad. Had to take off the cruise control assembly, etc.

When I put the new one in, there was a metal piece that slides into a shaft area of the tube. If you're missing a part that went down that tube, try to get something magnetic or one of those little grabbers that come out of a cable perhaps. Maybe that'll help in your situation.

Email me directly if you have any questions, I'm not on the forum that often.

jeff