I think I've got it really close now. Yes, the main problem after setting up the two CraftingStepInteraction items seemed to be that the sim just wasn't picking up the notebook. Everything else seemed to work. I made a wild guess that maybe there wasn't really anything wrong with the new CSIs. Maybe CSIs just weren't made to pick up the item? So I tried inserting back affordance #13114 BEFORE the two new CSIs in the staging file, like so:
(replaced gt and lt symbols below with as there doesn't seem to be a code option, not sure how you did that, maybe as I'm a new member)
13114
9925384858017238595
15304797812437575096
Sims would then go over to the notebook, pick it up and start writing like before, only now it would update. Resuming a book also worked (apart from the issue below). Once the book was completed, I got a copy of the book in my inventory and I could sell it normally at the mailbox.
The only problem, at least that I'm seeing (there may be hidden ones!) now is that the progress stored on the memory stick goes away if I save and reload the game. Other than that a sim can write a book, cancel, resume, etc. and the progress circle updates.
