This small hole, near the top of pic 1, goes through the body. A straightened paper clip goes through with no resistance, and I can see the end within the body - nothing gets in the way of the clip. So that's not it - or it has already been loosened at the trafo end.
The ribbon element at the other end is not yet loose....maybe if I get out the propane torch
Note that the hole is lined up with the vertical placement axis of the ribbon element (pic 2).
It looks like the XLR mating assembly is a separate piece from the main body. It's kind of hard to see in these lousy pics, but the finish is slightly different between the main body vs the XLR endpiece, which has the serial number & labeling.