You don't see the Massey carts too often. I almost bought one last fall but the guy wanted $180 for it and it was in Jersey. If he would have dropped to $120 I would have drove over to get it. It is hard to find them not rusted out because they are one of the items that are usually left outside and not stored inside.
PS, the catalog does show two very different trailers, not just taller sides. The whole trailer is much heaver, and has a round draw-bar tube. If I remember right, it has a top hinged dump gate on it as well. I have never seen one in person though,
It would be pretty easy to just paint a universal trailer up to match though, I am going to do that to my trailer one of these days. (plus have decals made)
I am planning on making a "Massey people mover" to match my MF-7 when its done. I want to get a trailer and put some bench seats on it and paint it to match the 7. I plan to use it at the tractor shows for hauling my family around.