I have produced three PDF documents from the 7th edition document
sources available at http://plan9.bell-labs.com/7thEdMan/
Copies are avaialble from me and at Bell Laboratories.

Volume 1 has the Manual pages, sections 1 to 8.
Volume 2A has papers on General Works, Getting Started, Document
Preparation, and Programming.
Volume 2B has papers on Supporting Tools and Languages, Implementation,
Maintenance, and Miscellaneous

I thought it would be fairly simple and straight forward, but it took more effort than initially expected. Because of this extra effort I am offering them back in this PDF format to place them along side the source. Today, they are much more usable in this form, especially since these things are not going to be updated. It can be read, browsed and searched on many platforms as well as printed to many different printers (not just PostScript ones)
These are most of the the changes I made to get them produced --
For volume 1: remove the page break ticks from tmac.an
header files needed for .so's in various man pages: /usr/include/sys/acct.h /usr/include/sys/var.h /usr/include/sys/dir.h /usr/include/sys/fblk.h /usr/include/sys/filsys.h /usr/include/sys/ino.h /usr/include/sys/stat.h /usr/include/sys/types.h /usr/include/sys/timeb.h /usr/include/a.out.h /usr/include/ar.h /usr/include/dumprestor.h /usr/include/grp.h /usr/include/pwd.h /usr/include/ustat.h /usr/include/time.h /usr/include/utmp.h
Place a \& in front of some lines beginning with . so it would be literal: man1/roff.1 man1/tbl.1 man7/man.7 man7/ms.7
For both volumes 1 and 2: added an old bell system logo into PostScript for \(bs in the sources
For volume 2: modify the tmac.s macros to remove the page break ticks.
uucp/network needs to be run through refer as well (fix in "run" script).
needed to make 4 figures (with pic, at the time of these docs, Kernighan hadn't written it yet) -- msmacros/ms: last page, Figure 1, arrangement of commands at the beginning of a document make: transformation paths diagram implement: Fig 1 & Fig 2 (got what they looked like from the bstj of '78)
the missing learn references were taken from the learn.ms file found in: http://cm.bell-labs.com/cm/cs/who/bwk/learn.tar.gz
replace .ND dates for some files so they didn't get printed with the date it was troff'd.
the missing C reference manual was replaced with the PostScript one for the 6th edition available at http://cm.bell-labs.com/cm/cs/who/dmr/cman.ps
fixed the typo in ratfor/m0 of the word "oe" to "one" (I really don't want to be an editor but this has bothered me since the first time I saw it long ago)
fix the uprog/cwscript sed script because the old symbols in constant-width are no longer the correct mapping.
All the additional files I created are in v7add.tar.gz. /* Side note: if you want all the v7 headers (slightly newer than the * ones I included), you can get them (and all v7 sans source) at * ftp://minnie.cs.adfa.edu.au/pub/PDP-11/Sims/Supnik_2.3/software/uv7swre.tar.gz * this is provided by the the PDP-11 UNIX Preservation Society. */
Production procedure: (refer,pic,eqn,tbl,troff)'d, PostScript'd and distill'd them into PDF I ran into a distiller bug so I needed to slightly modify many of the PostScript files just before distilling (this did not change the contents of the documents)
added blank pages as needed so that sections and papers started on an odd page number so that they can be printed double-sided
after they were in PDF I added the bookmarks: Volume 1 being man pages, the bookmarks are at each section. The best way to find something here is to just use the acrobat reader's search (binoculars icon) function. Volume 2 bookmarks are on each individual paper.
The PDF doesn't look exactly like the original because troff now produces slightly different output for PostScript devices.