James Sullivan

Here are more photos attached:

Hello again, attached is more photos of the handle and it's markings. Thank you for all of your feedback. I am still trying to figure out if this may be a fake so attached are the photos. Thanks

Hello, my father had picked up this WW2 Bring-back Katana that is in resemblance to that of a Kunitsugu Katana, the maker is Kyowa, the type is Shobo-Zukuri and the blade is to date the time of around late 1700's to early 1800's. The issue is when we had first received the blade it was in great condition, little grit from wear but the blade overall is in great condition. However my father took it upon himself to apply mineral oil to it as well as this Metal Polishing / Corrosion Polishing material known as "Flitz". Once applied and wiped down he then put the blade inside of the sheath and has been letting it sit on our basement for about 3-4 months. However recently I went to go remove the blade to clean it and now it is showing these signs of white bloches and brown spots. These had just begun AFTER he used those materials on the blade and put it back into the sheath. Currently the Katana is sitting outside of the Sheath. I re-applied mineral oil to the blade however it isn't coming off and I believe it may be a chemical reaction issue. Attached are before and after photos, the Flitz used and the markings from underneath the handle. My question in particular is what are these bloches and brown marks and is there anything I can do to remove them without damaging the blade? Is the blade permanently messed up? Can this problem be fixed through a professional? Is the Blade and Swoard genuine to the traditional era before WW2? Or is this blade a WW2 era make? Thank you.