Wow, perfect timing, Uniface! My brother and I went hunting yesterday and we find blades kind of like the one on the link you provided - but they are much smaller (maybe 3 inches?). We are still pretty new to this so we just put our finds in our backpacks and laugh saying, "it looks like something". The problem we were having is all of the blades people show are thin and flat but most of the ones we find usually have that center ridge. So, thank you very much!