Arthur has provided us with a wonderful array of photographs. A visual feast for us! Many, many thanks, Arthur.
I am still not certain that we have uncovered all the 'secrets" of the various transformations of this tiara.
I think there are a number of anomalies in the information available to us -- or I should say the information I am aware of.
While on page 178 of The Queen's Diamonds Robert's says that the emeralds were permanently removed from the Delhi Durbar tiara in 1922 and later adapted for the Vladimir tiara, the Royal Collection site gives a date of 1927 for Arthur's 9th photo. The information is conflicting. Either one or other is inaccurate.
In his book Roberts states, on page 196, that the Vladimir was adapted in 1924 to take 15 emeralds and quotes a Garrard's ledger of 15 April 1924 for 28 pounds ten shillings for this work. 10 emeralds from Delhi Durbar tiara were used plus 5 others. The ledger entry would seem to suggest that this is the time when the change was made, but I know this does not mean that the 10 emeralds were not removed in 1922. I am just pointing to an anomaly.
Given the reference Roberts makes to the Garrard ledgers, I am inclined to think that the Royal Collection's date of 1927 for Arthur's 9th photo is incorrect, as the emeralds adapted for use in the Vladimir tiara were fitted with small hooks to enable them to be used in that tiara. I suspect that the 'leaf surmounts" of the emeralds from the Delhi Durbar tiara were not changed when the emeralds were used in the Vladimir - but, of course, I could be mistaken. If the leaf surmounts for the existing 10 emeralds from the Durbar tiara were retained, then only five other emeralds had to be set. If so, then the cost seems to reflect such a scenario.
The National Portrait Gallery of UK has photos from the same session as Arthur's 9th photo, but the gallery has confusing, different dates for photos which are obviously from the same session. Some photos have a generalised date of the 1890s, one photo has a date of 1895 ( but given Queen Mary's visual age characteristics - these are incorrect) Others say the 1920s. It would seem that no precise date has been ascertained by the National Portrait Gallery for this photographic session. I am unaware of any other institution which has tried to date this particular set of photographs. So, perhaps the jury is still out on the precise date of these photos.
We still have to explain (or account for) the entry in the Garrard ledgers dated 19 March 1912. Roberts' quote is -- "Altering centre of large emerald & diamond Tiara, mounting Your Majesty's 4 small brilliants & 17 roses as ornaments on either side of large drop brilliant...'
Re the changes seen in the 1922 photos where Cullinan III was placed much lower into the central portion of the tiara: I think that substantial changes were made to the upper central portion of the tiara. Both Arthur and I have posted photos of the tiara in this version.
I don't think a simple re-positioning of the Cullinan would have been possible. I suspect that the whole section was probably remodeled as a removable insert so that the central element of the upper portion of the tiara could be changed at will from that photographed at the Delhi Durbar to that in the 1922 photos. I suspect that only such an adaptation would explain the changes over the years, and which would explain the description given by Roberts in the work billed by Garrard in 1912 - "On 19 March 1912 "Altering centre of large emerald & diamond Tiara, mounting Your Majesty's 4 small brilliants & 17 roses as ornaments on either side of large drop brilliant...'
Why else would so many more diamonds be needed on "either side of large drop brillant..."?