Hi Tim! To restore image probably you can change dump script to copy data (dd command) in the other way. But I wouldn't dare to do it - it may work as long as your system is working ok. If you corrupt something you won't be able to run the script and you won't be able to restore the firmware (maybe JTAG can help). So even having that backup you cannot feel safe.
BTW. You are the only person I know that has copy of Aura firmware. Can you please share first 16MB of it? I would like to test if Regal technology will work on other devices:
https://www.mobileread.com/forums/sho...d.php?t=226739
I can see you have Kindle Paperwhite and Kobo Mini so you may be interested in, too