Help re-installing older Valve (exposed Sigma)

[nyfooty]

Hi, I have pulled the valve from the wall to replace cartridge as it can only be accessed from the back. I am awaiting shipment of the cartridge. I have inserted some caps to stop the water for the moment. I have tried to put the valve back for testing, and I am struggling to line up the threads properly. The two pipes become a little pushed out to get valve in place. I am wondering if I was meant to take off the elbows and the wall connetor bits that you can see in the photos, put those on the valves and then put the whole lot back. Clealry I am a DYIer. I tried two plumbers to fix the leak which is the cartridge both said, I need to replace the whole shower as they have not seen that valve before. That's why I decided to take it off myself. Any ideas on putting it back?

To be clear, putting the valve back together is not the issue, I am fine with that, its re-attaching it to the pipes. Take elbows and the other connectors off first? Or try and squeeze it back in which I have struggled with.

 

[breplum]

I can't tell from the pics if the other nuts near the wall are union connections or just tapered threaded connections.
It would be ideal if they were union connections so just undoing them and building it back.

 

[nyfooty]

I can't tell from the pics if the other nuts near the wall are union connections or just tapered threaded connections.
It would be ideal if they were union connections so just undoing them and building it back.

Thanks here is a better pic - the nut at the wall is not free spinning - to take the elbow off I would need to spin the elbow - I guess that means I have to leave the elbows in place and just try and force the valve back in place?

 

[breplum]

I’m afraid you appear to be correct. I am not stunned…the mfrs. of ‘designer’ plumbing fixtures are notorious for stupid elements. That is why we refuse to install many of those products.
Those union nuts (that you have plugs in) don’t slide out of the way?