I believe that in several cases, Field (who in contrast to Menkes was provided quite generously with official information) was quite deliberately mis-lead for the purpose of reducing the overall size of the Windsor jewelry collection in general, and particularly regarding the provenance of pieces in private possession (for example the true amount of the Greville inheritance) and also the number of jewelry gifts received over the decades of QE II's reign. If you go through the 'mistakes' from the original edition which Field allegedly made, almost all of them fall in one of these categories.
In other words, I believe the 1970 tiara was never dismantled but simply remained unused for forty years until it reappeared two days ago. If the identical scroll setting of the stones isn't enough, then IMHO the best tell tale sign is the distinctive setting in a frame with two 'stilts' lifting it up in the center - definitely the same back then and now.
--Previous Message-- : : I'd better explain. It might not be a : perfect match. : : From my reading of Field she says that 'head : ornament' of the Queen's (worn in Canada in : 1970) was used in 1971 to add to the : aquamarine tiara the Queen had made in 1957. : : However, we now think we have seen Sophie : wearing that head ornament in 2012. : : I'm now thinking, if Field is right, then : other gems have been added to the carcase : and that head ornament is now worn by : Sophie. Not a match after all. : : Or Field identified the wrong 'head : ornament' and the 1970 one was never : dismantled. : : : --Previous Message-- : I'm very sorry Nellie, but from your two : posts : I actually do not comprehend your : alternative theory about what the tiara as : worn by Sophie might consist of...? : :