How interesting, maybe it always belonged to the Royal Collection and was on loan to the Museum of London? I seem to remember red velvet in the case for the pieces that are now in the Countess of Wessex wedding tiara. I wonder whether this blue which they call purple is new, or whether there are two cases with different colored fabrics.
Interesting that the fleur de lys in the circlet are identified as Prince of Wales feathers. If the circlet was made for Queen Victoria, why would they be PoW feathers? I can't remember pictures of either Queen Alexandra or Queen Mary wearing the circlet when they were Princesses of Wales.