What I would like to see and is something that I've kicked around creating, is, for lack of better words, a key-word index. Basically, I have chicken, what are my chicken recipes, I have basil, what are my basil recipes. I have tomatoes, what are my recipes that use tomatoes, and etc. Especially helpful around harvesting time - I have an abundance of X, what can I make or do with that? Possibly use it as a stretch goal? Make it apply to the digital copies with links? Example: I have chicken, look up chicken in the index, see all the recipes that use chicken, select one and click on the link to go to that recipe in the digital copy.
In addition, this sounds a lot like Carla Emery's book, but updated with pictures. You might check in her old book to see if there are any things you might also like to include in yours.