The back strip on this 1970mahogany dreadnaught has separated from the back plate on one side by about .006". See pic attached. The strip that covers the seam on the inside of the guitar is loose in a couple of places, but not along it's entire length. There is also a small section on the bottom of the neck block where I can fit a .003" feeler gauge under it by about 1/2". Other than that, all of the back braces seem to be stable without any loose spots.The back itself seems stable overall. If I squeeze the guitar sides, in an attempt to close that small gap and bring the back plates together, there is no movement.
What should be my course of action here. Is this just the celluloid back-strip shrinking over 40 years time?
Should I run some hide glue or Tite-Bond under the center seam and the neck block inside the guitar, and leave the back strip alone?
Should I fix what is loose inside the guitar, then run some kind of adhesive in that .006" opening on the back? Some CA glue or something very thin? Tite-Bond? Something to ensure that the back seam stay stable?
Thanks for any help!