It's relatively easy to bring up a V6 PDP-11 Unix under the Ersatz-11 PDP-11 emulator. This page (and ancillaries) tell you how to do it, and provide a number of useful tools to go with V6 Unix. (I ran into a number of pitfalls on the way to getting V6 running, using RK05 disk images from the TUHS archive, but this short writeup will tell you how to avoid them all.)