Dooh!!!!!!

Looking again at the last photo from Kaz (copied above) and it shows the housing slightly turned as if partly towards folded position... so I’m wondering if this is the key because if I rotate through 90’ as if folded, this reveals two Philips screws.

Looking at this, I’m wondering if this facilitates separation of the upper body of the mounting plate from the base. This I’m thinking would then allow my to feed the plate inside of the body and then reconnect to the two parts?

There is as can be seen in the photo, a fairly meaty looking spring, so before I attempt the separation, is there a risk I wont be able to put it back together without specialist tools??

Thanks again ...