What puzzles me about this TSUBA is the fact that the TAGANE marks in the NAKAGO ANA have been left untreated. Usually you will find them filed down to fit a blade. Concerning patina in general, the surface has a lot to do with the appearance of it. Some HIGO TSUBA have a very smooth surface, allowing for a deep black sheen. Patination of iron may vary from brown to deep black depending of the chemicals used. Some rust spots (?) seem to have been treated with a sharp tool, which gives the impression of an amateurish handling. Traces of wear from SEPPA are almost not visible on the photos, so together with the 'clumsily' executed hills that form the background, I have an impression that it may be a very recent TSUBA.