I'm really just trying to figure out what I have and doing some light detective work. Either it is an early piece and I have not been able to find references (most likely) or it was made but an exceptionally skilled armorer. Both situations are positive in my view. Here is the loose notes I have:
Major Premise/Theory: What I have is a tsuba that was done by Nobuie's disciple/apprentice, Saotome Ienori. This would have been done in Nobuie's lifetime.
Minor Premise/Support:
Signature does not appear to be same in this example: https://www.bonhams....o-period-circa-1800/
Counterpoint:
A) https://tsubakansho.com/tag/kamakura-bori/
--> May reference book as Nakamura 1963. Not validated yet.
B) Tôken Tsuba Kagami, Banzuke was published around 1800s that ranks tsuba makers from the beginning through present.
Materials I have to try to tie everything together: A) green papers (yes, I know they are not ideal and it will take time for me to get resubmitted because I will not mail this); B) publication, the tsuba is published in a book, but I do not have the name of the book, just scan of pages AND the book is what makes this reference;
C) From Markus Sesko, the reference: "And this brings us to the tsuba makers banzuke that I was talking about (see picture below). It is titled Tôken Tsuba Kagami (刀剣鍔鏡) and was compiled by Noda Takaaki (野田敬明, 1759-1825) some time during the Bunsei era (文政, 1818-1830). ... It is also interesting to learn that two Saotome artists are found within the top ranks. Anyway, it becomes clear that this banzuke focuses on tankô (鐔工), i.e. tsuba craftsmen...". ...Saotome Ienori is listed as a top tsubashi.