Thanks for that.
I called my nearest B&O authorised repair center and they walked me through the process, recommending that I remove the clips from the unit and glue them to the doors using the glue marks left on them. They recommend a two-part Loctite product called 5-minute epoxy here in the US btw.
They also recommend buying new doors for a guarantied repair.
The only part I'm a little unclear on is removing the clips....
I've read that the doors (when still intact) come off by turning them as pages of a book.
But I fear breaking anything!
Also, which end is up on the doors? The black paint that conceals the glued-on clips is about 1/8" closer to the edge of the glass on one end of the glass than on the other.
Anyone notice this and remember which way is up?
Had I known the one remaining was going to come unglued I would have marked "this end up".