Can be seen perfectly on the wonderful 'back-view', Beth posted at the top of this thread.
Back view (to repeate)
Back view, frame marked One can spot a tiny screw on the left side and I'm convinced, there is an equivalent on the right and most probably also in the middle of this frame. The 'extra' frame for the crosses is visible at the bottom - it's a gap between the crosses' frame and the circlet itself.
Oh, how I love such 'back-view' pictures, who disclose the secrets of these wonderful jewels .