For my repair I gave up on trying to do the job without removing the turbo. In my case the gasket right at the turbo was not leaking, so I never took those two bolts off. What I found was that one turbo nut was loose, and most of the exhaust manifold attachment nuts. So, the turbo and exhaust manifold came off. It turns out a lot of the leakage down the side of my engine (on the 1982 300D) was drainage from the intake manifold. One gasket seals both intake and exhaust manifolds as they are in-line. The new manifold gasket is an improved design and does not leak. Turbo does not leak now either. Big improvement overall.
But the car was on ramps for a long time.
While in there I did the POR-15 anti-rust treatment under the battery (and the battery plate too).
Originally I thought maybe that straight section of turbo drain tube would push downwards out through the oil pan opening. It doesn't. But now my oil pan does not leak either.
The main reason I have the collection of MB diesels is to drive one while maintaining or fixing up the other three. When you get down to just one that is driveable - its time to get serious with the repair efforts.
Ken300D