Jewish population in USSR in 1933 was around 2.5 million according to this source:
Overall population of USSR in 1930s estimated around 160-170 million (of course in flux due to famine/genocide and also increases in some other areas).
YIVO (Yiddish Scientific Institute) has an article Russian Revolutions of 1917
YIVO also conducted some talks on the subject in 2017. In https://www.youtube.com/watch?v=J2O2yZT49_A, there is a segment on Jewish representation in the Secret Police (49:00), with the role of Jews in the NKVD being discussed at 55:00.
JTA Russian President Vladimir Putin said that at least 80 percent of the members of the first Soviet government were Jewish.
I thought about something just now: The decision to nationalize this library was made by the first Soviet government, whose composition was 80-85 percent Jewish, Putin said June 13 during a visit to Moscows Jewish Museum and Tolerance Center.