I seem to recall that this, or a badge in the shape of just the black segment, appeared in the Oberlandbund anniversary book back in the 1970s, but I can't seem to find my copy right now. So I believe that this, or a somewhat similar design, existed. Unfortunately, there's nothing about this particular example to suggest that it is of freikorps-era manufacture, so it might be one of those fantasy pieces being cobbled together from old and new designs.