Thanks guys! I feel a bit silly now. Maybe there's still value in posting it? Let me know. The things that it does are:
1) Uses shadow copy to avoid interfering with Aurora running.
2) Makes two copies and compares them to ensure consistency - if Aurora was writing to the file(s) it starts the process over again to ensure a good backup.
3) Compresses the backups. With my new game I'm getting about 90% compression with 7-Zip (25MB file goes to 2. 5MB).
4) Date/Time naming scheme means the files are always unique and sortable.
5) Generically written, so can be used to capture just the main Stevefire. mdb, all Stevefire. mdb. X files too from the wrapper, or other things (e. g. use it for something other than Aurora if you like).
6) Configurable parameters, including the timer and the backup location, and can turn off each of these options (shadow copy, compression) based on preference.
The one thing it does not currently do is manage old backups, e. g. the revolving backup scheme done by the wrapper. Compression means you can keep a lot of them around, so far I don't see a strong need to delete them. Thoughts?