Are there any PDP-11 Qbus systems? 
Yes, for suitable values of "PDP-11".  The ones I'm familiar with were
sold labeled "LSI-11", I think, but they are real PDP-11s for any
software purpose, just Qbus instead of Unibus.  (I could be slightly
wrong, since I never was all _that_ familair with them.)
  If so, which version of which operating system do they
run? 
Any that isn't tied to Unibus-specific hardware, as far as I know, but,
again, I was never very familiar with them, and that was years ago
besides.)
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