Nice set Tim,
An old fashion stackable.
When you get the set apart see if there used to be a safety screen/ grille under the chassis. I noticed alot of the sets us VKr's come across are missing the bottoms. I have a very curious little grand daughter, can't wait to get her hands into things. It's in the genes, I suspect. I wonder if some of the manufactures never even used underside shock prevention.
Ed