The lover's knot tiara worn by the Fürstin von Waldbourg Zeil was bought at auction in Geneva in the 1990s. It is the one owned, long time ago, by the duchess of Cambridge. It was then inherited by her daughter, Augusta duchess of Mecklembourg Strelitz and transmitted to princess Augusta's grand daughter, princess Jutta, wife of the Montenegro crown prince. All this was mentioned in the catalogue of the auction. Actually, the necklace worn by the fürstin of Waldbourg Zeil, although it much more recent, was also in the same auction. It seems it was bought (I guess by the prince of Walbourg Zeil for his wife) in order to make a full set.