Caravels were generally 6" narrower than comparable Airstreams of the same year. All Argosy Minuets were 6" narrower than standard Airstream and Argosy products of the same years.
The wider bodies didn't start until fairly recently, and it didn't make a difference how short a trailer was, it was the same width up till that point. The wide bodies are 25' and longer in the newer trailers only.
Meddle not in the affairs of dragons, for you are crunchy, and taste good with ketchup.