… So, what you want is modify the faced-pages left/right margins and so adjust the layout to take this into account!
Your problem is that there are unanchored boxes on the current pages and that you use ID CS6!
pretty much... was hoping for a magic fix that wouldn't mean going over each page again. balls.
THANK YOU SOOOOO MUCH Michael! This worked like a dream. Seriously cannot thank you enough. It would have been a total nightmare otherwise.