In FE, there is no 
lowering c
1 to c1. The patent inaccuracy was corrected in EE and GE3.
Compare the passage in the sources »
category imprint: Interpretations within context; Differences between sources
issues: EE revisions, Accidentals in different octaves, Inaccuracies in FE, GE revisions, Omission of current key accidentals, Errors repeated in GE
notation: Pitch