Version 2

If a Device (in the Device table) does not have a match to one in AvailableSources, it is considered "dead" and is not visible to the Devices page. There should be a way to show these dead devices and either remove them (and optionally their media/events) or attach them to unconfigured devices in AvailableSources (e.g. if you switch out a bad solo card for a new one, you will get un-attached Devices in the Devices table).

Perhaps there should be a good way to handle the latter case to en masse associate a group of ports from a non-existent card to the unconfigured devices on a new card.