This project entailed item-level cataloging of rare 78rpm shellac discs from the Offenbacher Mozart Collection at the UW Music Library, with a focus on materials recorded before 1923, which entered the public domain in 2022. After complete and accurate bibliographic records had been created, additional research and data remediation allowed a previously unidentified set of audio files to be associated with metadata and uploaded to the Internet Archive. Cataloging physical and digital elements from this unique research collection has created an unprecedented level of access to rare sound recordings from the early 20th century.