Welcome to the group
Just so you don't get blindsided, hereabouts "Fiberglass" means "Molded Fiberglass" or basically seamless construction, as is the Casita
Other, conventional construction, trailers, made with fiberglass sheeting, don't enjoy the lighter weight
and superior longevity that molded construction, with far fewer water entry points and generally more robust construction, enjoy.
FWIW: The TrailManor line is known for it's substantial weight and, as always, posted dry weights are just a starting point, and are usually quoted for base model rigs without any options installed.
There is a listing of "Real World Weights" in the General Chat section that will give you an idea of what loaded trailers actually weigh.
Good luck in your search and keep asking questions.