No. This s just complicating matters too much. By 1925 when the bandeau was purchased from Garrards, Queen Victoria's wedding gift had already been broken up and all diamonds used in creating Queen Mary's Fringe Tiara.
Roberts quotes the Garrard bill for this bandeau tiara, as having cost £688; which is a high price indicating that this tiara was not commissioned from existing pieces, which was in fact a direct purchase. There is no need to speculate when we have the solid facts; that this was not a commission using Queen Mary's old diamonds, it was a direct purchase from Garrard stock.
--Previous Message-- : Yes, but what exactly did she purchase. She : already had the emeralds. Could have the : base of the Queen Victoria's necklace be the : base of this tiara? Why would she make a : tiara with the same base as the Girls of : Great Britian tiara. Looking at the book, : most of the time the royals supplied the : diamonds, emeralds, etc. The jewelry : supplied the new design. I don't think the : book gave enough info for me to conclude it : was a new design, since the emeralds are not : new. The book didn't go into specifics on : this one. :