Birdhead

I was laboring under the false assumption that Japan would confiscate the sword and destroy it if they determined it was fake/inauthentic/non-traditionally made. I'm reading now that this isn't the case and they will just return it to you. That's why I was so focused on getting feedback on if it was "authentic" or not. I definitely would like to send it off to Japan at some point and see what they might say. There is someone here who contacted me about a professional polisher here in the states that they know, so I suppose taking it to the polisher for an expert evaluation will be the next step. Thank you everyone.

Thank you everyone for your assistance, I appreciate being able to understand more about the sword. Since the sword is not of collector quality, would you advise against restoration? I originally wanted to keep the sword in a healthy state (as you can see it has some deterioration in the pictures) but if it has no value then I would spare the effort. I understand there are not many people who can do this sort of thing professionally.

As stated in the OP, I'm aware the chance this was actually made by Yasuyo is slight. In particular the 2nd to last kanji seems very incorrect to me. By "authentic" I just mean - traditionally made Japanese sword. If it was just a cheap forgery, then that probably would not justify restoration. I am curious to discover why someone would sign their work as someone else though. If this is in fact a traditionally made sword, then one can be sure the smith, whoever he was, underwent a lot of training and effort to learn his craft. It's strange that they would go through so much for their work and then sign it as someone else. I guess what I'm saying is I'd just like to know as much of this sword's story as possible.

I'm in Oklahoma, sword is in Georgia. The ultimate goal for me is to get it properly restored by an expert if it's authentic.

I've got some closer pictures. The condition seems pretty bad. What do you think? Would this be worth taking to an expert to get appraised and restored?

Apologies if you've seen this kind of thing before, we're looking for some opinions on what this sword might be. My grandfather brought it back from the war. From my novice research, I would guess it was made during the war or shortly before. It does have a signature, "Ippei Yasuyo." I understand that this was a smith of high renown and that the likelihood of this signature being genuine is small. My grandfather sent a rubbing of the engraving to the NBTHK in 1960 and they merely replied that it reads Ippei Yasuyo and gave some details about the era and place where he worked. I'm not sure whether this was simply a literal translation of the signature or if it was intended to confer some kind of authenticity. Even if it's gimei, we're still excited to learn more about what the sword may be. I'm attaching some pictures and hoping to get some more detailed pictures soon. This thread - Has a very similar example. The handle looks virtually identical, suggesting the fittings at least were mass produced (although the tsuba looks slightly different.)