nice boké (just tried to make an example shot @F2 by Otus 55/1.4)
I could not mount new Nikon cameras to this PB-6 bellows (camera's grip interferes with the standing base),
that's why I used Sony a7R2 with an adapter. Result > http://www.pbase.com/kkawakami/image/162209045

(G-S90m head) + (M42->F ring) + (Nikon PB-6 bellows) + (F->E adapter) + Sony a7R2 + (Manfrotto 055 + #168)
This very Manfrotto tripod always has #168 head for some bellows or Fujinon binoculars with the quick shoe.
This one is my first Manfrotto tripod, later I bought black one (same #55 model + Kenko head) for general use.