I always take the stance with Katanas or katana parts....they are unbelievably important culturally to the Japanese. If you take a close look at the quality of construction of them, and there is ANY doubt about it being made with the utmost care and respect it’s probably a knock off. Even if they are simple they are still made with care. You won’t see unfinished bits or shortcuts taken. The absolute worst of the Japanese katanas were the machine made military swords made late in WWII and even those weren’t too bad. If there is any doubt about its quality, even if it’s old, it’s likely not.