You can remove them from the Removed Items database, and then MC's Auto-Import functionality will pick them up again as "fresh".
The Removed Items database is a hidden database within your MC Library. It is relatively easy to access, though you have to make a custom View or Smartlist to see it. To see only the removed items database items, make a Smartlist with the following rule:
~d=rWhich equates to
Modify Results:
Limit Database to Removed in the Search Wizard.
Once you have that, you can simply select the files there, and "delete" them again. When MC asks how you want to delete them, choose
Remove from Media Library only (the top option). It will remove them from the database. Occasionally, you have to do it twice if you have stacked items in there so just refresh the view and make sure none of them come right back.
From that moment, Auto-Import will consider them "new", though it won't "trigger" on them until some other change is made on disk. You can run the Auto-Import scan manually, though, and it'll find and re-import them, or it will do so by itself next time it does a full scan.
However, you may find it more convenient if you need to access this regularly, to make an All Databases View. To do this, you'll need to make a new "top level" view in your Tree not under Audio, Video, or Images (so that it isn't filtered to show only those Media Types). I call mine "Advanced" but you can call yours whatever you want.*
Then, under that, make a new Panes-style View called All Databases (or whatever) with the following characteristics:
Set Rules for File Display search:
~d=a ~sort=[Filename]Add an Expression Category called Database with this expression to Group-By:
FileDBLocation()- Leave Expression to Display blank
- Sorting: Ascending
- Matching: Match Any
- Grouping: unchecked
I find it also useful to add a Location pane, so add a second Category of type File Path, and leave the select path box empty. You can also add any other categories you'll find useful (mine has Media Type, Media Sub Type, File Type, Artist, and Series, but YMMV).
Then, you'll have a view that can see all of the MC databases, sorted by Filename/path, and you can subfilter them by type, path, or whatever you want. It is handy to have. Some of the other databases can occasionally be handy. The Bad one, for example, is files Auto-Import has seen, but has "determined are bad" and so ignores on future scans. If you have a file that got erroneously flagged, you can use the same method described above to remove them from that list (show the database, select the files, and remove them from MC). Most of the other databases in there aren't exceedingly useful, but they are neat to see.
* It is worth noting that you only have to make a separate top-level Advanced View if you want to be able to see all Media Types within the View. If you only care about Audio, you can skip this step and just make the All Databases View underneath Audio in the Tree. Or, of course, you could uncheck Use parent scheme rules for file display when creating it wherever you'd like and it will show all Media Types even if you create it under Audio in the Tree. But, it'd be weird to go to Audio to access a View that includes Images, Data files, and Videos, so making the Advanced top-level view makes more sense if you use multiple Media Types in MC. Plus it is handy to have for other organizational reasons. You can put "utility" and "tagging" Views your family doesn't need to see in there.