Good Day, Respected Kindle Devs!
First, a heartfelt thank you for all your work. My jailbroken KT5 is literally the favorite device in a house full of geekery. Owe you guys for all your hard work.
Second, apologies in advance for any poor forum etiquette...no intention to offend.
Third: In my excitement to get a PW3 (G090G105XXX, FW 5.8.11, Rev 3243010037) jailbroken I bricked my device

foolishly attempting a downgrade after disregarding the warnings on this thread:
https://www.mobileread.com/forums/sh...d.php?t=294964
Had to wait for a year or so until my brilliant Dad was able to get me serial port access to the device, but now I'm able to "diag>exit login" to root on what I assume is the /dev/mmcblk0p2 partition.
We used the great information posted in this thread:
https://www.mobileread.com/forums/sh...d.php?t=267541
I failed to backup my device because I didn't study enough and only found knc1's backup thread after the kindle was bricked.
https://www.mobileread.com/forums/sh...d.php?t=289690
Since I have already proven my stupidity I'd like to avoid doing further damage by *precisely* following any directions or advice you'd be kind enough to give.
I've attached the serial logs. I'm using minicom and Ubuntu 18.04 live CD across a TTL-232GRG-VREG1V8-WE cable. Unable to get USBnet working (appears dropbear is broken). Also unable to mount /dev/mmcblkp4, the other partitions (except boot0) appear okay.
Goal: Jailbroken PW3 with all the goodies your brilliant minds have developed.
Thank you very much in advance, and THANK YOU for all the great work you have done and continue to do here!