That's cool, Floyd. Didn't know they had another model in the works!
You could also keep an eye out for an Eriba Puck. Only the roof is molded fiberglass; the rest is aluminum skin over aluminum frame. They're popular with the vintage VW crowd. Under 1000 pounds, but hard to find. The Meerkat by Little Guy is a modern knock-off of the Puck with a base dry weight
of 900 pounds. They both have indoor galley space and stand-up headroom thanks to a pop-up roof section, but either would probably go a little over 1000 pounds loaded.
Not much else with solid walls and stand-up headroom I can think of even comes close to meeting your weight
requirement. See the sticky thread "Trailer Weights in the Real World" in the General Chat section. Note that both of the sub-1000 pound trailers were empty shells undergoing renovation
. The entry point for an all-molded fiberglass trailer is around 1300 pounds once you add minimal gear and supplies. Most 13'ers weigh in the 1500-2000 pound range.
That does not stop sellers from claiming they have a sub-1000 pound egg trailer. Like the unicorn or the Easter Bunny, it's fantasy.