The truth is I've forgotten what I've previously known about this. I thought there was a Memento.db file in the memento folder in internal storage (I'm on a tablet.) But I don't see one right now. I'm too lazy to check my settings to see if I moved it to another folder.
Anyway, my recollection is that all entries of all libraries are kept in a Memento.db file. What is not in there are external files (images, audio, video, bar codes, ...) and slice'n'dice settings. You should be able to copy that around and get what you're after. Links are all in there.