Have you done a search on the site for those two ebook readers? There are only a few threads for these two readers.
Try these to start.
NUUT:
https://www.mobileread.com/forums/showthread.php?t=11463
Soribook:
https://www.mobileread.com/forums/showthread.php?t=28347
There's also a brief bit of technical information in the
wiki for
Soribook.
Dreamer