Hell, we were all undergraduates at JHU running the UNIX facility and it
wasn't no unskilled position in the pre-fsck days.
I remember having to describe the filesystem in detail and the vagaries of
icheck and dcheck before I got the job.
We never ran PWB UNIX directly (having our own heavily hacked V6 kernel) but
we picked and chose from the various distributions
(PWB, V7). I remember the pwb shell.
My first after graduation job (while waiting for my clearance) was helping
the QA guys set up sccs and many other things that came along with PWB so we
could manage the project software controls not for any of the IBM operating
systems but for RSX-11/M.