Here is my understanding.
Team Trillum in calgary (trilliumtrailers.com) is using the original Trillium 1300 (13') molds for their Outback Trailers and they have been building them since at least 2002. Trillium RV seems to actually own the Trillium Name (note that Trillium is not part of the Outback trailer name). Team Trillum in Calgary will be making the bodies/frames for Trillium USA and then the final assembly for the trailers is done in California. The parts and look inside of the trailer looks different then the outback, I really like the stove/sink
Trillium RV will be building a 4500 model for the summer and I do not know if in fact Team Trillium is building the body. However, they are asking for feedback on the floorplan on the 4500 (which I sent them) and you may be interested in doing so too.
Feedback on 4500