There are lots of different fiberglass trailers. Some people use the name Casita as a generic, but there are Casita, Bigfoot, Trillium, Escape, Oliver, and a whole bunch more plus a number of out of production brands, such as Boler and U-Haul.
iRV2 is a RV Life Forum and a sister forum to this is the Fiberglass RV forum
The same log in you use here will get you in there too. You will find lots of helpful people and information on all types of Fiberglass trailers, be they 25 ft Bigfoots or 13 ft Trilliums.