Well when I did my BYC search it was a topic that had been discussed at length before on here quite a bit. Apparently this must happen quite often so there must be some sabotage going on somewhere probably like it does with pure bread golden retriever dogs and some looking more like Irish setters than golden retrievers and not having webbed feet or their double coats when they are supposed to have both traits to be a true retriever. There is just some cross or mixed breeding going on or folks trying to pull one over on you if they think they can get away with it and it be over and done with and nothing more done about it. Which is probably the position your in. You probably have a fat and sassy healthy perfectly good chick but it’s not a full blooded Orpington that’s all and to a keen eye like yourself you picked it up but the average Joe wouldn’t have known the difference. I don’t know what you can do about it??? I will say this if it’s even half Orp plan on a good eater, personality, people person, and flock member, they rule the flock, and they are the watch dogs or guard dogs of my flock. They are the protectors of my nine among my flock but yet the are still gentle basically. They are nine weeks old and haven’t found their beak uses and full understanding and damage it can do or pain it can cause yet. They will peck the crap out of my hand for attention or pets or food if I’m not fast enough for them. But they are smart birds and protect one another from danger and are problem solvers for the flock. They were the first to use the nipples on the waterers and they were my strongest flyers at first. So good luck with your dime bag! Lol!