I have hung my rear axle from its mount and attached the trailing arms to the axle. I have also read a lot here about, and can confirm myself, the difficulty of attaching the front of the trailing arms to the body mounts.
Having spent 34 years as an engineer (automotive type), I am naturally reluctant to "force" things into compliance just to be done with it, so I started taking measurements to find out where the problem lies.
With the axle shafts horizontal, the center-to-center distance between the two axle mounts for the trailing arms is 906 mm on my car. The front of the trailing arms are almost exactly the same distance apart, so that's nice - nothing appears to be bent.
HOWEVER, the two body mount studs at the front of the trailing arms are exactly the same spacing as the span of the rear axle alignment tool that has been discussed here often - 877 mm. That means that in order to fit the front of the trailing arms, I have to "squeeze" the front of the trailing arms toward one another by 29 mm to get them onto the body mount protrusions and studs.
After asking myself, "Why?", and analyzing for a while, I came to the conclusion that there is no neutral position for the rubber bushings in the Pagoda rear suspension. With the car simply sitting still, the fronts of the trailing arms are forced toward one another by approximately 29 mm, however in full jounce or full rebound, the trailing arm mounts on the axle tubes are at least that much closer together, thus relieving the side-to-side squeeze. But at the same time, in jounce or rebound, the trailing arms are "twisted" relative to the body mounts, imparting a different kind of stress into the bushings. If one tried to design out one kind of bushing stress, he or she would end up designing in more of the other kind of bushing stress.
The more I work on this car, the more I appreciate the sophistication of the Mercedes engineering that went into it. I can now install my "come-along" and force these parts into alignment for attachment without feeling like I've done something wrong.
If anyone disagrees with my analysis, please let me know your logic before I get too far along and break something.
Tom Kizer