I've had this for a few years now and finally got this out again in hopes I start using it. Its been in storage for over 2 years and still works just the joint between the camera body and viewscreen body. its too delicate than I realize when I put it away. I've the service manual for this but I can't tell how this part is suppose to work since it pivots and such.

I'm no expert on this by anymeans, but your picture of the area of the camera in question is excellent and it looks like the black plastic ring/collar/thingy may simply either be keyed to the fitting hole on the camera. If that's the case then it should have a specific position it needs to be oriented to to push back into the camera body. Other thought is that maybe it clips into the camera body, kinda hard to say for sure since we can only see it from this one angle.

there doesn't seem to be away at least I tell to fix the plastic piece in the middle. I'll have to get some the sticky squares
to get it more sturdy even though it will loose the ability to move. I just don't want the wires to break.