by Ken Task.
Check the contents of the .log files if they are larger than 0 bytes. Could give a clue.
The other files/folders one can delete manually - safe to do now as those appear to be failed attempts. However, the next time you do a backup/restore, check that same folder to see what is there. Moodle should 'clean up' that area leaving only 0 byte .log files IF backups/restores were successful. Anything else that remains should probably be inspected with whatever tools you have to use. Can't tell you what to look for specifically. Do compare .xml files and their contents with the related folders ... example: files.xml with 'files' folder contents.
'spirit of sharing', Ken