Unarchiving archived forms

A user on one of our teams inadvertently archived around 80k records. We want to unarchive them but I suspect there are records among them that actually should be archived. The report output listing all archived forms doesn't show when the form was archived - is there a way to see that bit of info as it would be very useful to determine which records need to be unarchived.


Just to add to this, I have backups of couchdb, blobdb and postgresqldb from before this happened and could restore those if required. Would that be the only option, or perhaps there's a SQL update I can run on the DB to revert all archived records archived on a certain date?
Thanks again