We know that the frame of the regal circlet is in the Museum of London, that the diamonds were used for Queen Elizabeth QM's crown, and that the alternative elements (as you discovered, Nellie) are in the wedding tiara of the Countess of Wessex. This means, as Trond says, that the tiara in Norway is a separate piece. My question would be which piece Queen Alexandra wore with Queen Victoria's small crown. Since that was early in her husband's reign, I would think it was the regal circlet.