Consolidating to a Library - weird stuff?

Normally I keep all media in an external folder, separate from the Library. I'm needing to consolidate half a dozen films now on different drives -- onto a single large drive. I've decided to have a Library for each film -- that contains all the media for that film; so I can move films around easily from drive to drive.

Every time I do this I find some of the media files don't end up in the Library, only alias's pointing back to the media still in the original external media folder. Each time this happens I simply drag that missing media clip from the external media folder over into the new-and-improved Library, replacing the alias with the actual original media. This works.

In one case I've got this weird thing happening: I get an 'alias' for the clip, which is connected to the clip in the original external media folder; AND I get a version of the original clip, now in the Library, but with an appended (fcp1) in the title. ????

When I open the new consolidated library in Final Cut, and do a 'Show In Finder' for one of those clips ... it takes me to the version in the new Library (but with the appended (fcp1) in the title.

I find this weird. Has anyone ever seen this before, and what might be causing it? I don't like the idea of all those alias's sitting there, am tempted to just delete them, but that may mean when I open the Library in FCPX all those clips will no longer be linked. I can relink them, but only to the clips now in the Library with the odd appended titles. And I can sense, but not yet see, potential issues down the line ...