How do I reinstall the trunk latch cover on my '64 cuda?

Mine is a 66’ and also I have the tail light covering plate - I bought that from Layson’s. #rick@laysons
It’s a one piece cardboard like product to cover the tail lights and wiring from behind.
Anyhow it is needed to seat that cover. I’ve removed all 3 years and they all tied in with the factory cardboard cover plate. On the cars. Is you cover from a barracuda originally and not from a Dart or Valiant with a proper sedan style trunk? Just asking as I am not 100% certain.
Syleng1