Interior wood

[Thomson Model A]

Is it possible to replace just one piece of wood in the cab of a 1931 steel top truck? It looks like the rear top piece of wood in my truck has some water damage and the trim on the top rear of my cab has come loose on the drivers side.

 

[Big hammer]

I am not a truck guy. So the trim piece is on the outside or inside? Surly some of the truck guys will chime in.