No they're not Golden Comets. The point of Golden Comets, or Red Stars, or Black Stars, or other hybrid types, is that they are sex linked at hatch. Not only do they lay really well, as you have found, but they can be sexed at hatch. They are produced, as Fred said, from 2 totally separate breeds. If you keep them and breed them back, you've lost the initial sex linking and hybrid vigor. You probably have some very nice excellent brown egg layers (I detest the term "mutt" for chickens) that will probably produce some more really good egg layers, because of their good genetics behind them, but they wont be any particular breed. Just good old barnyard hard working brown egg layers. Why dont you try and cultivate local interest in your extra eggs? I sell out of my eating eggs every single day. People love them.