I found his Pinkas Mohalim at the National Library of Israel.
After the war, Gershom Scholem was sent to Europe to try and retrieve Jewish libraries. He eventually arrived at Offenbach, Germany. Many Jewish books that had been stolen by the Nazis were kept at a warehouse there. He managed to take some back with him and today most of these are part of the rare book collection at the National Library of Israel.
I asked to have it digitized and hopefully in a few weeks it will appear online.
After the war, two prominent Jewish scholars, experts in Judaica, were sent by the Hebrew University to find and retrieve Jewish books from Europe. Gershom Scholem eventually arrived at Offenbach, Germany. Many Jewish books had been stolen by the Nazis and kept at a warehouse there. (see: http://www.ushmm.org/museum/exhibit/online/oad/hist2.htm )
The books were being given out to various Jewish and academic libraries. He managed to smuggle some back with him and today most of these are part of the rare book collection at the National Library of Israel.
This Pinkas was among the Offenbach collection.