In Debian, the package "dpkg-repack" allows restoring to an installable deb package the files which are installed.
Let's say... Thunar !
# dpkg-repack thunar
dpkg-repack: File not found: /usr/share/doc/thunar
dpkg-deb: building package `thunar' in `./thunar_1.2.3-4+b1_i386.deb'.
# ls thunar*
thunar_1.2.3-4+b1_i386.deb
If there are not too many dependencies, you might be able to avoid downloading a package, once a while (if you need it for another machine, it can be convenient at times).
I met with errors, because I had removed the content of the /usr/share/doc, but otherwise installing it should work.
