uck-remaster-chroot-rootfs in command-line environment

I'm using uck-2.0.1 with the minibuntu 7.10 live CD image. I want to create a command-line-only live CD with several customizations that will not be installed to the hard drive of any machine.

So far, I have successfully unpacked the ISO and the root filesystem. However, because I do not have a GUI environment on my server box (which is where I'm doing the build), the uck-remaster-chroot-rootfs script fails when trying to mount the X11 sockets. I tried manually chrooting to the remaster-root directory and running apt-get from there, but I got a whole pile of perl and locale errors, and the package installation failed.

I can very easily customize the files I want in the various locations in the unpacked root filesystem, but I also need to install a few other packages (openssh-server, for example) into the filesystem before I repack it and remaster the ISO. Would somebody please be able to point me in the right direction? I know just enough to be dangerous on my Linux systems, so explanations on any difficult bits would be greatly appreciated.