From memory the guy that made the trailer (I think he made a couple of them) was based in Blackburn/Burnley. He couldn't get production off the ground because of the cost and couldn't get type approval. I think he did approach a couple of trailer manufacturers who didn't show any interest.
I went down the road of converting a sailing dinghy road base trailer which I use mostly during summer when we go away on holiday in the caravan.
https://www.rib.net/forum/f49/carava...ler-86495.html