Folks, have a question. I have a 1934 Plymouth coupe, and the previous owner/builder channeled the body into the frame. Not bad, but I'm 6'4 and it has a wooden thing in the roof. It doesnt appear that there was a cloth roof, and from what I have found it was originally built in Canada. I'm attaching pics of the wooden block tbing in the roof, and wondering if its important, how to remove, etc...
The insert was replaced with metal. I can see the welds in your pictures. Fabricator must have cut a piece of plywood to hold the metal while welding was done. If you could remove the ply you wouldn't gain much headroom.
I see hex nuts. I can only surmise, the plywood is fixed with carriage bolts and likely slathered with fiberglass/bondo on the top side. (???) .