I *think* the B also had an SD card. Take a look through this thread
https://www.mobileread.com/forums/sho...d.php?t=211265
If I'm right, just ask in that thread for an SD card image. Ideally what you want is an SD card image for a B that has been upgraded, and the creator of the image has done a logout from accout to remove the database but leave it at a new F/W level.