I had this tsuba for quite a few months, I found similar in books, and I was sure it was a kamakura-bori piece of late Muromachi period, ca. 1400-1550.
It was even papered.
Recently, I acquired a look alike tsuba, also attributed to kamakura-bori style by the seller, a knowledgeable person.
The second tsuba, however, was signed Kunihide, whoever he was, and had clear mokume treatment of the surface.
Now, there are two similar pieces in books:
1) Dr. Walter A. Compton Collection, 1992, Christie’s auction, Part II, pp. 14-15, №16: “A kamakurabori type tsuba, Muromachi period, circa 1400. The thin, six-lobed iron plate is carved on each side with a wide groove that follows the shape of the rim, and with six scroll lines and a single thin circular groove. […] The hitsu-ana was added at a later date, circa 1500-1550. Height 8.3 cm, width 8.6 cm, thickness 2.5 mm. The tsuba was initially intended to be mounted on a tachi of the battle type in use from Nambokucho to early Muromachi period (1333-1400)”.
2) Robert E. Haynes Catalog #9 on page 24-25 under №23: “Typical later Kamakura-bori style work. This type of plate and carving show the uniform work produced by several schools in the Muromachi period. Some had brass inlay and others were just carved as this one is. The hitsu are later. Ca. 1550. Ht. 8.8 cm, Th. 3.25 mm”.
A question I would like to address to community is: How come a kamakura-bori tsuba got a signature and mokume surface treatment?