Unfortunately this is not really feasible at the moment. The config files are indeed stored as individual files in the file system, but they are given a unique identifier as a file name, and all the metadata associated with that identifier - for example, the identify of the device and the timestamp of the backup - is only recorded in the Manager database.
There is one way you could do this that will be available in a few months that may be appropriate for you. It is a bit convoluted, but if this ability is particular important to you, you can PM me for more details.
Cheers,
Dave.
