Yes, I think so too. Markus Sesko also wrote to me on this sword. Here is his message:
"The signature reads " Igami Sadahiro" (井神貞弘). That said, the maker seems to be a "little mystery". For example, he signed his name also with the characters (伊神) for "Igami" and I think that it might be the Gifu/Seki-based smith that I have listed in my book which bore the real name Takai Shirō (高井四郎). As his father Sadatsugu bore the family name Takai too, I think that Sadahiro might have change his family name to Igami at a certain point in time which he then wrote in two different ways. But maybe Igami was just a pseudonym. Unfortunately, not much information is known on this smith so maybe we will never know.
Maybe you have heard about my Gendaito Project. I am going to create a free website will all information on Gendaito smiths available. Would you give me the permission to use your pictures for the website later? In this case, I can update information if anything is found in the future.
Best regards,
Markus"