This piece is not shown in the airplane manual so I did not know it was missing.  I met a Stinson 108 owner who lives in Nebraska while I was visiting Beaumont and he offered to stop by and see how I was doing.  He’s rebuilt several Stinsons and currently flies the one owned by his dad.  He showed me a few pointers and where a few things went that I wasn’t certain.  One thing he pointed out is the fact I was missing some support for the rear panels.  Since the panels were not installed when I got the airplane I didn’t know they were missing.  So I made some out of the leftover wood from the ceiling piece and fit them as he directed.

Recreated piece is circled in red.