Happy the year of 蛇 Snake!
a perfect first-piece-of-the-year to share for a great beginning
三尺刀 Sanjaku-to (swords with 3 Shaku blade length) itself is already very rarely seen in Nihonto market, which most of them are stored in museum, Jinja shrines and private collections, not to mention a fully mounted 大太刀Odachi/ 野太刀Nodachi like this particular piece
this sword has a Nagasa blade length of around 三尺五寸 3 Shaku 5 Sun (~106cm) and a full length of 五尺一寸五分 5 Shaku 1 Sun 5 Bu (~156cm), solid, healthy and strong.
As a size refefence, the Katana with black 天正拵Tensho Koshirae has a Nagasa of over 2 Shaku 4 Sun (~73cm), the Katana with purple 突兵拵Toppei Koshirae has a Nagasa of around 2 Shaku 3 Sun (~70cm)
the Koshirae is mounted with 一作 Issaku full set copper fittings, including the 笛巻塗りFuemaki-nuri style Saya which is reinforced by over 50 copper rings! Combined with the dark 青貝Aogai lacquerwork in between the copper rings, with such extrodinary length, the overall Saya design reminds me of the image of a large slithering python.
The long, large and thick Tsuka is mounted with a set of large 大目貫O-menuki in the design of 蛇Hebi snake, which the large iron Tsuba has gold inlay of 北斗七星Hokuto-Shichisei "Big Dipper".
Photo records of such pieces are very rare to find, and personally, I would definitely want to see more of such samples published on internet for the sake of study and enjoyment.
Hope you enjoy the photos, and hope a great year of snake is waiting!