Hey gents,
Bit of thread necromancy here, but I've just finished work and thought I'd take the opportunity to give interested parties an update. Please excuse this lengthy delay, these last years have certainly been interesting.
As I mentioned in my long ago reply I got the chance to have my blade appraised by Andrew. I'll include a copy of the appraisal and relevant photos if I'm permitted. If sharing appraisals is poor form, please let me know. Without further ado, a wall of text.
DIMENSIONS:
Nagasa (Length): 69.7cm
Mihaba (Width): 3.0cm
Kasane (Thickness): 0.7cm
Sori (Curvature): 2.2cm
PROVENANCE
The nakago (tang) of this sword is mumei (unsigned) and shows no signs of an attribution. It appears to be o-suriage (significantly shortened from the bottom of the nakago), it has two mekugi-ana (peg-holes), the lower of which is likely the original, but it’s possible the original was even lower and is no longer present. In other words, this was originally a much longer sword.
Since the nakago is mumei, my appraisal must be made based on the workmanship in the steel, considering the details of the steel are mostly obscured in the sword’s current condition, a window has been opened and I’ll be basing my appraisal largely on the workmanship revealed in the window, but also on the sugata (shape of the sword).
The sugata of the sword displays the following features:
The curvature is quite deep.
The tip is small-medium sized.
The width of the blade is about average, but the width of the shinogi-ji is comparatively quite wide.
The shinogi is quite high.
The iori-mune is steep.
These features would point me towards a sword of the late Kamakura period/early Nanbokucho period, made in the Yamato tradition. (Kamakura period = 1185-1333, Nanbokucho period = 1333-1392)
(Yamato tradition means it was made in a style founded in the Yamato province, current day Nara prefecture)
The window has revealed some very interesting and high-quality workmanship:
The hamon is based on suguha, with ashi, yo, sunagashi, uchinoke and nijuba activities. The brightness and clarity of the nie is very good. (See attached pics hamon1 & hamon2)
The jigane is a mix of masame-hada along the hamon, mokume-hada along the shinogi, and some ko-mokume in between. There is a lot of ji-nie attached to the mokume-hada, there are plenty of chikei, and some faint utsuri. The quality of the forging is very good. (See attached pics jigane1, jigane2 & utsuri)
The boshi is ko-maru with hakkikake. (See attached pic boshi)
The features revealed in the window fit into the Yamato tradition well, in fact the jigane seems to be a textbook example of ‘Shikkake-hada’.
‘Shikkake-hada’ is a particular style of forging pattern often found in works of the Shikkake school, which was a prominent Yamato-tradition school that spanned from the late Kamakura to late Nanbokucho period. In the books, Shikkake-hada is described as having prominent masame-hada flowing along the hamon, with burls of mokume-hada sitting along or just above the shinogi, exactly like the jigane revealed in this window.
The hamon is a good match for the Shikkake school as well, it’s of a quality that I’d expect to see from the school, and all the activities I see in the hamon are common traits of the Yamato tradition. The boshi also fits well for Shikkake.
Therefore, I conclude that this sword was most likely made by the Shikkake school. Though, I can’t discern which individual smith made it, as the school has very few signed reference examples to compare with. The vast majority of swords made by the Shikkake school have school attributions, rather than individual maker attributions. But judging by the sugata, I’d say this is likely a fairly early example of the school.
There is a possibility that the sword was made by a different Yamato school, as I’m only able to see the workmanship clearly in one area of the sword (other possibilities I considered were Tegai school or Senjuin school), however I believe the odds are definitely on Shikkake.
And there we go, the origin of this mystery sword becomes more clear. I'd like to thank everyone for their advice and information. Also a special thanks to Barry and John for helping me get this far.