I don't know which date is the reference. The wedding date? Princess Sophie von Württemberg lived from 1818-1877. In 1839 the Princess married the Prince of Orange.
1839-1849 Princess of Orange Friedrich Wilhelm III, King of Prussia until 1840 Friedrich Wilhelm IV, King of Prussia 1840-1861
1849-1877 Queen of the Netherlands Friedrich Wilhelm IV, King of Prussia 1840-1861 Wilhelm I, King and Emperor 1861-1888
If the collier was given by the then King of Prussia as a wedding present, then it was in the last year of the life of King Friedrich Wilhelm III. He was the father-in-law of Princess Marianne of the Netherlands, it seems more plausible then that the collier came back into the Orange-Nassau collection via Princess Marianne?
Anyway, not so important. The fantastic pearls are still present and let us be happy about that.