My dad found this in a thrift store in AZ a few years ago and I was wondering if anyone could tell me more about it. I took the best pics I could,the hamon goes all the way to the tip but is very thin for the last 10 mm or so and there looks like a grain opening close to the hamon towards the last third of the blade that I tried to show in the close ups. Also there seems to be one very near the tip on both sides. Is this a real nihonto?