Are these Heisey Hen on Nests?

These two hens on nests look very similar, with one being slightly smaller than the other one. They appear to be Heisey hens, and the diamond H mark on the blue one seemed to confirm this, but I have heard that some knock-off Heisey hens were produced in the 1980's. I hear that the diamond H looks a bit different on the fakes, but I can't find a description of what it looks like. Can anyone tell if the blue hen is authentic or fake? I'm new to hens on nests, so I would appreciate any help you can give. By the way, the blue hen has a sizeable chip on the other side of its beak. Thanks!