Do you keep Project files local as well as on the NAS?
What is your backup routine / workflow?
In my case I Save to a Job specific folder (Local)
I do 'Save Copy as' to (BACKUPvers#PROJECTNAME) to same folder.
Backup application (FBACKUP 4) does a verified copy of the Project Folder to another different local drive.
I manually copy that to a NAS every regularly / every so often. (Maybe I can automate that with the Back up Application though - must check)