I never liked the German jazz rock bands due to their total lack of "black" feeling. Where American bands had r & b as reference ther German bands had a rock feel, which is too hard and stiff in comparison. Just my opinion, of course.
I still have the LP by Head, Heart and Handy who were a magnificent live band, but the album is rather bombastic sounding with too many overdubs. Then I have the album by Frankfurt's band Voices, another great band live, but the studio recording is a far cry from that. Dauner's solo albums are great.
Now that Dauner, Mangelsdorff, Kriegel and whoever was involved are all gone, who owns the rights? I have no idea.