I have edited one of my pictures to show more clearly where you can find the aluminum framing if you are purchasing an older (1999-2002) Trailmanor. Older than 1999 was probably wood framed, although I think I have heard about one or two that were aluminum framed. I believe most built after 2002 were aluminum framed, but I could be wrong. I'm not aware of anyone on this site observing wood framed Trailmanors after 2004 or 2005.
Even if you have an aluminum framed Trailmanor, there is still some wood used for the bag seals, vent openings, and a few other places. These pieces are relatively easy to replace if you are handy. It took me a few days to replace one of the bag seal wood strips, but I do work slowly.
In the picture below:
The circled area on the left is the end of an aluminum bar used around the perimeter of the wall. Other than the pocket stops, there is no other aluminum framing inside the wall.
The circled area on the right is the framing inside the pocket stop. This may be aluminum, wood, or aluminum with wood behind it.