An article from the Boston Herald, April 16, 1945, states that one deposit from the Rothschild Museum in Frankfurt was found in a Hungen castle that dates back to 1571. The castle was the home of Princess von Solms-Braunfels. She had fled to Bavaria but her husband James Pitcairn Knowles remained. This is where this article takes a strange twist. The article says, "The custodian who holds the keys to the cellar where the loot was found is 87 year-old Alfred Teissinger who is a Titanic survivor"
More research lead to a genealogy site that lists that his birth as October 12, 1865 and that he died August 6, 1949. His date of birth is confirmed as October 12, 1865, born as Franz Alfred Daniel Maximilian Theisinger in Dorn-Duerkheim, Hessen-Nassau, Preußen, Germany, son of Maximilian Josef Theisinger and Johana Elisabetha Susanna Josephine Wolff.
The missing 's' in his last name may be a typo. He appears on the 1901 UK census as a German-born British national, boarding at a Southampton address, listed as Alfred Theissinger.