Mike, K-Line did sell items with those circus wagons before they went under, for certain, but I don't know if they went back to the Marx era. I don't recall IK-Line selling them in the earlier part of its corporate history either. I can tell you that the only thing in that set from Lionel tooling is the aquarium/mint-type car in the upper left. I guess they use it as an "animal cage" car of sorts.