RIP David, it's been said above but he really was a great force for Kobo on this forum, and via the Calibre plugins.
This is a loss felt by many here, my condolences to his family.
It may be a little crass, but I feel it's more likely to get some views from here than where it is. Peter has put out a request to those who have received the disk images for all the various Kobos over the years from David to attempt to unbrick them. See:
https://www.mobileread.com/forums/sh...d.php?t=348904
Again I apologize for possibly coming across a bit crass, but this is with the goal of continuing the help David so kindly offered all of us here.