Is there a way to tell which files in /etc were modified?

I want to create a mirror of my existing Debian server. I modified many files in /etc, and I don't want to redo everything by hand or download huge mirrors. What I thought of doing is 1. Download a list of all files in /etc 2. Download a list of all .deb packages installed Then, on the original server, 1. Expand all .deb into /tmp/etc1 and see which /etc files they install 2. ls /tmp/etc1 > /tmp/listOfOrigEtc 3. ls /tmp/etc > /tmp/listOfEtc 4. diff /tmp/listOfEtc /tmp/listOfOrigEtc > /tmp/listOfFilesToDownload 5. Download all new etc files 6. Using find, see which /etc/ files were *modified* and download them Is there a way to do this **using a single command**?