Well I've tried all variations of KUAL listed on the threads below
https://www.mobileread.com/forums/sh...44&postcount=1
https://www.mobileread.com/forums/sh...d.php?t=225030
I tried the recent signature files after each installation when the original displayed the developer signature message. The only different message I got was when installing a file for around a decade ago which returned a message that the signature had expired or words to that affect and the software needs updating.
If anyone has managed to get this working on a gen 4 (looks like the attached). If so can the filed be zipped up and attached to a new post.