Yesterday I watched an episode of the 2017 BBC program, Antiques Roadshow, in which the final item featured a Romanov family photograph album which had apparently been given to an Englishman, William Lincoln, in Ekaterinburg, by one of the maids to the Romanov family. She had said to him: "I want you to keep this for me. If I am found with it, I will be shot."
There was also an extensive series of letters written by William Lincoln from Ekaterinburg to his family in England in 1918, during and after the imprisonment of the Romanovs. The AR expert accepted the authenticity of the archive and estimated its value at auction at perhaps 65,000 pounds. He expected a publisher to pay that sort of money for the archive, which had been held in private hands for nearly a hundred years.