another potato/woody X3/4 question

[Remy Indebetouw <remy@astro.wisc.edu>]

I've got a potato/woody pinned hybrid, and my main reluctance to just
dist-upgrade is related to this:

I appear to have both Xfree 3 and 4 (see apt-cache output below; I
didn't purposefully do this, parts of X4 came along with libc6-dev, I
think.  BTW thanks to those who convinced me that apt would not lead me
astray in a hydrid system.  deb packaging rocks once again).

I used a patched Mach64 server on my Dell I7K laptop (ATI Rage), so what
I'd like to do is configure and try X4 without trashing X3, or at least
know how to get back, so
-how do i tell if I have all parts of X4 (I thought this was x-window-system)
-how would i get back if it doesn't work?  restore the
old /etc/X11/XF86Config and what else??
-once X4 works can i just purge task-x-window-system to wipe X3?

Thanks in advance.


agave:~> apt-cache policy xserver-xfree86 xfree86-common
task-x-window-system xbase x-window-system
xserver-xfree86:
  Installed: (none)
  Candidate: 4.1.0-14
  Version Table:
     4.1.0-14 0
         50 http://http.us.debian.org woody/main Packages
xfree86-common:
  Installed: 4.1.0-13
  Candidate: 4.1.0-13
  Version Table:
     4.1.0-14 0
         50 http://http.us.debian.org woody/main Packages
 *** 4.1.0-13 0
        100 /var/lib/dpkg/status
     3.3.6-11potato32 0
        500 ftp://ftp.debian.org potato/main Packages
        500 http://security.debian.org stable/updates/main Packages
task-x-window-system:
  Installed: (none)
  Candidate: 2.1
  Version Table:
     2.1 0
        500 ftp://ftp.debian.org potato/main Packages
xbase:
  Installed: (none)
  Candidate: 3.3.6-11potato32
  Version Table:
     3.3.6-11potato32 0
        500 ftp://ftp.debian.org potato/main Packages
        500 http://security.debian.org stable/updates/main Packages
x-window-system:
  Installed: (none)
  Candidate: 4.1.0-14
  Version Table:
     4.1.0-14 0
         50 http://http.us.debian.org woody/main Packages