You are correct in that some techniques were developed independently , scientificly speaking "contact" is the normal way of passing along ideas . As a trained archeologists You can only rely on current evidence and carbon dating etc: The dates I gave you are correct , directly from smithsonian archives . There is definate proof that the early copper culture amerinds from the great lakes area were the first real tool makers that utilised metal . See article from central states archeological society. I guess best is ok but, not in a foot race, first is better. I have been a swordsmith since I was 17 , I am now 64 . I studied in japan for 11 years while I was in military. I only rely on good basic evidence not speculation. The indians did not claim they were first , archeologists from the area did. The amerinds are long gone . respectfully.......
James J Bieler Bubba-san forge