If we imagine that the British monarchy has been deposed and there are discussions about what the former royal family get I think each items would be discussed individually. Even items that predate the convention would probably be up for discussion. I can t imagine that the Delhi Durbar Necklace would be given up since it was a state gift nor the brooch form the Sultan of Turkey. I think it would also be difficult to retain private ownership of the suite given by the City of London to Queen Alexandra.

My personal assumption is that the items that Camilla was given will go to what I refer to as the Jewels of The Crown, to be loaned out and worn, and I also have imagined that they could be altered to fit the requirements of future wearers including resetting. I assume that it is the ownership that matters not the usage, since they were given to be used. The scale of the British Royal Jewels collection is getting ridiculous. My list of jewels owned by the Queen is seven pages long and is font size 8. I don’t see how long term ownership can be so casually regarded considering scale and value