I recently acquired a First Edition copy of Kav Naki, a classic work on Hilchot Gittin, the Jewish Laws of divorce. The copy had the signatures and stamps of Rabbi Ezra Kalischer, the Av Bet Din in Chernovitz. There is a responsa written to him by the Maharsham, published in Shu"t Maharsham Vol 6, siman 27, dated 1897.
Upon opening the book I discovered a stash of Divorce Documents for divorces that took place in Chernovitz mostly in the years 1961-1962. Chernovitz was under Soviet Union since WWII and the writing of Gittin was more than enough to get you in trouble with the authorities, but it appears an underground Bet Din continued to be active, even under Soviet Rule. Judging from the date, it appears the Gittin were written by a different owner of the book, other than Kalischer.
The same 2 signatures appear in nearly all the documents, that of
קלונימוס קלמן בן יחיאל מיכל
אברהם יעקב בן משה