Normally the UCS file is written to /var/local/ucs but my config files are large so there is not always room in that directory so I write them to /shared/tmp instead. If your configs are smaller you would not need to do that. If they are small and you want to keep multiple on box then I would add a date to the filename in the script above but then you will also have to prune them after your retention date.
There is more in my backup script to send copies of other files for off box retention and adding them to our Rancid repository.
Please note if you add this to the root crontab then you will have to re-add it each time you upgrade since the upgrade overwrites the root crontab file.