Pic on left is view from rear of the transmission. Pic on rt. is side view of tranny and a little motor. In both, the rear is angled slightly upward. Remember, motor and tranny are upside down.
In #60 and #68 it is the same motor, laying on it's left side. Compare that to the photo on the right in reply #57, and it looks like that one in #57 has been REVERSED. Who in the sam billy (hell) is providing these photos?
In 68, the tranny pan looks like it's missing. The engine's oil pan might be a goner too...but photo angles obscure.
That, and I'm not all that familiar with modern era Mercedes gasoline engines. Like in #68, at the back of the engine itself there is a round cover [center-left in photo]...which I don't recognize, but reminds me of covers that the old 2-stroke Detroit Diesels would have at the ends of the camshafts, so one could hang accessories like generator/alternator, pumps, or power take-off drives and clutches.
The backside of the engine doesn't appear to be blacked out, like the top (air plenum?) and front of the engine appear to be in #58. I can understand the plenum being black -- have seen enough of those, and can guess the front blackness) could be timing chain (or gear) covers, though the engine block itself not "black" which makes it look different from the backside.
What could be behind the round cover in the photo (and the smaller round cover adjacent to it also) I can't find a guess that fits well enough to satisfy. Not that the small covers are all that important, but just from curiosity standpoint, having myself been "inside" a few dozen engines and have some idea how things work.