My first reaction was they're not the same, and reading the discussion on the Royal Jewels Board, I still hold this view. However, I don't see the problem with the tiara being on loan from a jeweller. Yes the family could afford to buy a new tiara , but Tatiana is unlikely to need one. Perhaps Princess Charlotte's fringe tiara is not wearable without restoration, perhaps it has already been broken up. The necklace Caroline wears may not easily convert, so perhaps a loan was the best option.
The clips on the cloak interest me too - does anyone recognise these as a Grimaldi heirloom?