The Sunspot Number series is one of the longest-running datasets in astrophysics, maintained by SILSO at the Royal Observatory of Belgium (ROB). Although it was recalibrated between 2010 and 2015, inconsistencies in the data remain, highlighting the need for a full reconstruction based on original observations. This presentation focuses on recent efforts to recover and digitize historical sunspot data. Key contributions include the digitization of Prof. Wolf’s detailed logbook (1610–1918), known as the Mittheilungen, at ROB, and the ETH Zurich library’s scanning of old sunspot observation tables. These efforts are part of the FARSuN project, which aims to make historical data machine-readable and accessible. The presentation will outline the current status of data coverage, digitization progress, and quality control methods. The ultimate goal is to rebuild the Sunspot Number series using original data, not just corrections to existing datasets, to better understand solar activity over the last 400 years.