Lost & Found - The Brunswick Tiara

Revisiting my image cache I came across these two pictures.
One shows in old age, Princess Viktoria Luise, the dowager
Duchess of Brunswick and Princess of Prussia, wearing the
tiara that was given to her by the people of Brunswick
(or was it from her husband?) upon her marriage in 1913.

I had read somewhere that this particular tiara went AWOL
under the possession of her son, also named Ernst August.
It wasn't seen on the head of Chantal, the first wife of
Viktoria Luise's grandson, Ernst August. But, the tiara
made a startling reappearance at the Danish royal wedding
in 2004 on the head of Caroline of Monaco. Was it ever
missing or just misplaced? Or is this tiara a duplicate?