Trunk "divider" question

Hey folks,

(Car is a 1975 Dart Sport)

Long story short, I offered to help a fellow Mopar guy by sending him a tracing of the trunk divider that came in my project car since it was lying loose in the trunk. My question is, does that chipboard divider go on the backside of the bracing (so you can't see the bracing from inside the trunk, or does it go between the seat back and cross bracing? I can't recall from my original car back in the 80s, and of course I never had pictures of the inside of the trunk.