Period: Early/mid Kamakura. Between Sho-Kyu 1219 and Ryaku-Nin 1238.
Mei: Zaimei, signed, in the correct Ko-Ichimonji style, armorer's mark to the Mune: ICHI.
Sugata: Shinogi-zukuri, tori-zori, iori-mune, with bo-hi and soe-bi.
Overall length: 36.49 inches (894.00 mm)
Nagasa: 27.87 inches (708.00 cm) long.
Nakago: Suriage, 7.32 inches (186.00 mm), two mekugi-ana. The yasurime are too patinated to see properly, though they look to be kiri.
Kissaki: Chu-kissaki, 1.18 inches (30.00 mm). Kissaki is filled with o-busa and juka choji. Ichimae turnback.
Moto-haba: 1.12 inches (28.40 mm). Moto-gasane: 0.31 inches (7.90 mm). Saki-haba: 0.73 inches (18.60 mm). Saki-gasane: 0.19 inches (4.90 mm).
Sori: 0.88 inches (22.30 mm)
Hamon: The gunome-choji midareba hamon is undulating, rising high and low throughout. This is the mark of an early/mid Kamakura date. On one side of the hamon the obusa-choji crosses over the shinogi in the monouchi. Utsuri is not immediately discernible.
Hada: Ko-itame hada. Well grained, with ji-nie and small chikei.
Very good polish. As the photographs show, every detail of the workmanship can be seen. No flaws, ware, hagirae or bends.
In shirasaya; see pictures.
This beautiful sword has been with a UK collector for a considerable amount of time and he is only reluctantly letting it go, largely due to having children in the house.
The Ko-Ichimonji were the earliest of the Fukuoka Ichimonji smiths. Few of these smiths signed with their own name, but instead used a single stroke, "ichi". The school is thought to have existed from Kenryaku (1211 - 1212) to around Kenji (1275 - 1278), and to have been the progenitor for all other Ichimonji schools. This particular tachi is a likely product of the Ichimonji build-up for the Sho-kyu War 1221.
It is worth submitting this sword, along with its present papers for shinsa. The paper may be old, but you can use Tokubetsu Kicho papers to submit this sword for either Tokubetsu Hozon or Juyo papers. An o-suriage Ko-Ichimonji tachi with Tokubetsu Hozon papers will realise £25k or more. With Juyo papers it will realise much, much more; I've seen Juyo Ko-Ichimonji blades priced at £81k.
The last sword I suggested putting in for Tokubetsu Hozon passed with no trouble.