What a tour de force Thomas!! I found the post extremely interesting to read. It gives us so much to explore.

It is great to have these various rivieres sorted. As you note the complicated familiar history makes it more difficult to try to follow the various necklaces.

One possible suggestion -- could Queen Sophie's riviere have come from Queen Victoria? It is a long shot, but there are press reports that Queen Victoria gave her granddaughter a diamond necklace. Unfortunately the UK press did not give any further description or have any images. Some of the UK press reports mentioned that there wasn't any viewing of the wedding gifts, so it seems unlikely that any images will be found -- but who knows?