Originally Posted by zkat
For the sake of closure, I can also report that you've successfully unbricked my Kindle Touch.
I don't really know what killed it. I tried undoing some miscellaneous things I remembered I'd done, but it still wouldn't boot -- so I just replaced mmcblk0p1 and everything turned out alright.
You are welcome! I added your success report to the first post in this thread. That first post is not as short as it used to be.