I found this today:
- Notes for OS X Mountain Lion
- Open Notes.
- Select View > Show Folders.
- Create a new folder called Notes Backup in the On My Mac section of your folders list.
- Select one or more notes from your All iCloud folder. Holding the Option key down, drag the notes into the Notes Backup folder. A green plus icon should appear as you're dragging the Notes to the new folder. This creates a copy of your iCloud Notes on your computer.
- If you have an iCloud section in your folders list, but not an On My Mac section, you will need to create one.
- Quit Notes.
- In System Preferences, select iCloud. Deselect Notes.
- Open Notes. Select File > New Folder. Name your folder Notes Backup. Create a new note in that folder as a placeholder. Quit Notes.
- In System Preferences, select iCloud. Select Notes.
- Open Notes. You should now see a section for iCloud and a section for On My Mac. Follow the instructions above for making a local backup of your iCloud Notes.
So there actually IS an Apple endorsed way to create an additional copy which resides who knows where on your Mac and may or may not be restorable if your whole Library folder is copied... Hope this helps someone.
Found the Notes mbox under mail but it might be from Lion when all notes were sent to mail as I have one in both IMAP accouns. Not sure..
Don't get caught out with the hidden user library. Finder > hold down option key > Go. > Library.> Mail > V2 > IMAP address > Notes. mbox