They advertised those in the 80's. I remember one advertised in The Western Horseman that had a fireplace too. I think I might still have it stuck in a book somewhere, it was my dream trailer back then. Strikes me that until the invention of the push out walls these were roomier than your standard gooseneck conversion.

You'd definitely have to get RV plates with three axles.

My only question is, if they were coming back from a horse show, where did they put the horses with all those chairs and stuff in the stalls?

My largest regret is I think it's a wee bit bigger than I wanna tow with my 3/4 ton. I dig it.