Dear Nobody and Ray,
Thank you so much for your help.
One last thing eludes me.
If I understand right, the sword on EBAY was signed :
Okubo (大久保) Genba-no-kami (玄番頭) Tadanari (忠成) kyu ju ichi sai (九十一歳) kore wo sasu (指之) which can be translated "Okubo Genba (no) kami Tadanari, at the age of 91 years used or carried this sword".
My sword is signed :
大久保(Okubo) 玄番頭(Genba-no-kami) 所持(possession) 九十一歳(91 years old) 指之(wears this) which can be translated "in possession of Okubo Genba (no) kami, at the age of 91 years used or carried this sword".
Am I right in the translation of my sword ????
On my sword, does the mention OKUBO GENBA-NO-KAMI was enough to identify a person ? or is the name of a person missing ?
Last but not least, was it a normal structure of phrase used at that time ???? In short does it make sense ?????
I promise that after that I stop the questioning.