I have just been following your guide from page 8 and have got to enabling the USB connection. As I have said before my Kindle isn't actually bricked and as far as I can tell..
Do I just need to do the following...
1. copy over mmcblk0p1-k4-401 in Windows as I would do with a normal file to the USB drive.
2. Then using putty (already been set up when I did the screen saver hack, run using diags mode) run the following command
dd if=/mnt/us/mmcblk0p1.img of=/dev/mmcblk0p1 bs=4K
idme -d --bootmode main
Then I should have a fresh Kindle???