Creating a custom journal...? (not a recolor)

Hi, Happy Holidays! I'm still kinda new to the world of content creation, but for the most part i've mastered a couple of aspects like recoloring & changing in-game text (still learning how to make meshes/traits). But now i'm trying to make a custom journal and I can't figure out how to add the interactions. I already retextured a cc deco book mesh that I want to use, but I don't want to recolor the original one because my mesh is a thicker, slightly bigger book than the journal. So it seems like I would have to override the game journal since a deco book couldn't otherwise behave like a journal? The only thing is, I wouldn't want it as a default replacement I would want it to be purchased separately from the original one. Is that possible? I'll just have to live with the DR if not, either way can someone point me in the right direction? I've been looking for help for a few hours now & I don't necessarily know what tutorial or advice I need specifically.