Here's someone that pretty much got it right the first time, Wally Byam:
Then he went to copying the Bowlus for his production trailers. The Airstream Base Camp reverts to this form factor. Here's the traditional 'Prairie Schooner':
Here's my design that combines the two into a low resolution version of the aerodynamic template:
The cardboard model was made one night and is long gone. The update to it would be to use the 'Prairie Schooner' chassis with the wheels pulled into wheelwells.