I love the derailleurs. All parts could be repaired or changed ; but I can't ride with the crank : you need a very large BB and the arms are too straight : I touch with my ankles.
I haven't seen one quite like it before, and I don't know if it's a prototype, a rare model, or a Frankenstein job. The cage is like the longer road model, but the logo on the parallelogram is more mtb style. I can't figure out the black upper knuckle at all. Any ideas?