Wow! Anything you list here sounds like choice steels for these knives, especially at those prices! I really don't consider 12C27 at the same level as 440C or ATS-34, simply because of the carbon content, which makes 12C27 easier in blanking for the manufacturing process. Even so, I am with you, if I had my druthers, then I would opt for 12C27, simply because I have enjoyed using this steel. Easy to sharpen, descent edge-holding, very stainless and a bit tougher than some of the other stainless steels. On the other hand, I would not even think of rejecting 440C or ATS-34. The more I learn about your choices in this project, the more I am anxiously anticipating the results!
Thanks again, Dan!