@RoosterNZ. You could follow these steps:
- Use a program to batch rename your files, for example: "Adams, Douglas/Last Chance To See/Last Chance to See.mobi" to "Adams, Douglas/Last Chance To See/Adams, Douglas - Last Chance to See.mobi".
- Set calibre to add books' metadata using only file names with proper regular expression (Preferences > Import/Export > Adding books >
uncheck "Read metadata from file contents..." and edit the regular expression text box to suit file names' structure).
- Add books normally.
PS: Some free file renamers you can use:
Ken Rename,
Rename Master.