I would be fiercely interested in any more details around this. I'm sure many of us have seen Scotty from Strange Parts doing his headphone socket project, and the franken-phone built from spare parts, but it sounds like you're suggesting something even more than that.
Sorry, that's personal anecdote, not something I got from youtube or articles that could be cited. See my other reply: I'm not really suggesting anything more than what you can see on Youtube, just that knock-off iPhone parts that are easy to manufacture (body, battery electronics etc) exist - not the logic board though.
Citations, please!