I've recently been working on DemonLord, the gamebook series based on USR and I just wanted to share a couple of things with you.
First off, the title I'm running with is DemonLord: Mountains of Ember, which may give a bit of insight into what the adventure may consist of.
Secondly, I've drawn up a mock cover of the book. It's not fancy at the moment, but it'll be something along these lines. I really like the artwork (public domain) and it links in well with what the book is about.
One thing I've implemented is a system similar to DestinyQuest's, where you choose one piece of treasure out of multiple options. I'm hoping this will add some replay value and increase the overall fun of the game.