Originally Posted by Bob Coleman
It was not uncommon for sword fittings to be signed with a school name in lieu of that of an artisan. Examples include Soten and Myochin.
Thank you Bob, I'm getting my head round this (slightly!). Most of my collecting has been military-mounted swords and for that reason, I've not given koshirae much attention. I actually translated the "Nara" kanji and said to myself, "That doesn't sound like a (person's) name", completely overlooking the place name, so out went a cry for help.
Since Guy did the translation, I've Googled and found many similarly signed examples and in slightly differing hands, suggesting more than one person signed in that way, so I now assume it is "of the school" rather than one person's work. Never too old to learn!