Can you get some up-close photos of the hardware? The chains, nails, hooks and loops and anything metal might be the best way of determining age. I don't see any signs of wear or use that is normally associated with a child's toy in your photos, so I expect that this will turn out to be a modern reproduction. So if there is visible wear, chipped paint etc., pics of that would be helpful. Also look for a "gate mark". This is the mark or seam left by the mold the iron was cast in. Also take a look at the underside of the leather harness. If it is real leather, the reverse will be a natural hide. If it is vinyl, you will probably see some kind of man-made fibers