I think you have some excellent specimens there! If the first picture of the pullet is true to color, then she has it 'going on' in that department. The cockerel looks like he has a nice frame going and will add to it some more substance in the following months. Overall, I think the breeder's mistake is definitely your gain! One thing you may want to check that isn't visible, is for the bar of slate coloring on the back. This is one very distinguishing color difference between the RIR and the Buckeye. Along with that you want to check how the bird feels, as Chris already stated. Pictures are good at finding general, visible faults, but to truly evaluate a bird, you have to get it in your hands and see it with your own eyes, as a camera can also change their color, so to speak.