Posted by Hans on September 9, 2012, 4:58 am, in reply to "Re: Comparison"
Could it be that the diamond base of the tiara belonged to HM Queen Elisabeth of Belgium.
By wearing the diamond base in 1960, Lilian showed the world that she was accepted by the old Queen of Belgium. The perfect way to make the world clear that she was "royal" by wearing a tiara (base) of the previous Queen of Belgium.
In 1967, HM Queen Elisabeth was already 2 years death, so it could be possible that HRH the Grand-Duchess Joséphine-Charlotte inherited the base and wore it with brooches to form a tiara.