This is from the Library of Congress. In WWII, Western Trailer Company made wartime trailer housing - essentially travel trailers - using molded paper components. From the LOC website:
"Overcoming metal shortage is a big problem in trailer manufacture. Western Trailer Company of Los Angeles has been able to replace metal fenders (wheel wells) successfully with plastic material made by a new process. Paper of forty pounds weight runs from rolls to a tent containing a glue-like solution. After it absorbs this solution, the operator breaks its stiffness by wadding and squeezing."
![Image](https://www.tnttt.com/gallery/image.php?album_id=1344&image_id=163123)
"Wadded-up paper, impregnated with a glue-like solution is smoothed into place over molds in continuous layers. The material is self-hardening and self-compressing. When dried, it is sanded, sawed and drilled, and may be installed with nails, screws or bolts."
![Image](https://www.tnttt.com/gallery/image.php?album_id=1344&image_id=163124)
![Image](https://www.tnttt.com/gallery/image.php?album_id=1344&image_id=163125)
"Here, a worker shows a finished wheel well ready for installation. It is made of successive layers of paper impregnated with a hardening solution. The finished wells are covered with an asphaltic preservative paint."
![Image](https://www.tnttt.com/gallery/image.php?album_id=1344&image_id=163126)
In this picture, you can see the trailer corners that were also made using this process.
![Image](https://www.tnttt.com/gallery/image.php?album_id=1344&image_id=163127)
I don't know why something like this couldn't be scaled up to do a teardrop or tiny travel trailer.