This is kind of a odd case, which is ultimately the fault of the uploader, but it would be nice if you could workaround the issue.
The following is basically what is happening:
The person uploading to Usenet appears to have a buggy script which automatically downloads batch torrents, splits all files, and then uploads to Usenet.
Usually this is not a problem since the files are quite large, but a problem with Alt.Binz arises when a file falls below the split threshold, since the small files are still appended with *.001 (i.e. filename.ext.001) by that person's script, even though they have only a single part. Alt.Binz doesn't know what to do with these single-part quasi-split files which have only had their extension renamed.
If you could add a fix to detect and rename these quasi-split files like you do with normal split files, that would be great.