Iron tsuba of round form with design of lattice (kōshi-mon, 格子文) cut in openwork (sukashi), with low relief shallow linear carving along the bars. Well forged plate with brown-ish hue. To the right of nakago-ana there is a clear inscription of the character Shō (正), which is explained by Markus Sesko is follows: "The Shinsa obviously recognized more from the signature when having the tsuba in hand, i.e. they were confident to say it is signed "Shōami" but the rest is illegible (ika-fumei, 以下不明). That is, if they were just able to read the first character SHŌ (正) and saw that there were two more, most likely A (阿) and MI (弥), they would have put those character in boxes on the paper. Boxes around characters namely means that the character is not 100% legible but it can be assumed what it is." Momoyama or early Edo period. Dimensions: 85.9 mm diameter, 3.6 mm thickness at seppa-dai. Weight: 79 g. NBTHK certificate № 425069 with attestation: Hozon - "Worthy of preservation". A similar tsuba is presented at Japanese Sword Fittings from the R. B. Caldwell Collection. Sale LN4188 "HIGO". Sotheby's, 30th March 1994, №15. The description says: "A rare early Kamakura-bori tsuba. Nambokucho period (late 14th century). Of circular form, the dark plate carved and pierced with a gate design, the struts with double engraved lines. Unsigned. 8.5 cm." The lot was sold for 1,840 GBP. We have two possible explanations of the discrepancy between Sotheby's and Shinsa/Sesko attribution: 1) either Sotheby's or Shinsa/Sesko were wrong in their attribution or 2) these are two different pieces, one - Kamakura-bori from the 14th century and another - Shōami from 16th/17th century. Anyway, I would consider my piece as a Shōami tsuba of Momoyama - early Edo period, just for the sake of modesty.    

Iron tsuba of mokko form decorated with trellis, vines, foliage, and gourds inlaid in brass with details carved in low relief.

NBTHK: Tokubetsu Hozon №2003186.

Momoyama period (1574 – 1603). Dimensions: H: 85.5 cm, W: 79 mm, Thickness (centre): 4.8 mm. Tsuba of a similar design can be found in this collection [TSU-0373]. In that example, the plate was later pierced with geometrical mon-like openwork to resemble Koike Yoshirō's handguards. More about this type of tsuba here.

Shingen school (or style) tsuba of round form with an iron core of spoked-wheel shape, with its centre covered with a copper plate decorated with star-shaped punch marks. From this copper plate outward, the body is formed by brass and copper wire (flat and twisted) in a weave pattern. Both hitsu-ana are outlined in brass with a raised rim. Copper sekigane. Unsigned. Edo period, 18th century. SOLD   Height: 98.0 mm, Width: 97.4 mm, Thickness at seppa-dai: 6.0 mm. Weight: 290 g. NBTHK certificate №436696: 'Hozon' attestation. Citing "JAPANESE SWORD-MOUNTS IN THE COLLECTIONS OF FIELD MUSEUM" by Helen C. Gunsaulus, Assistant Curator of Japanese Ethnology. 61 plates. Berthold Laufer, Curator of Anthropology. Field Museum of Natural History, Publication 216, Anthropological Series, Volume XVI; Chicago, 1923; p.45: "An unusual group of tsuba popular in the late sixteenth century and afterwards is made up of those guards known as Shingen tsuba, a name which was derived from a sixteenth-century warrior, Takeda Shingen (Takeda Harunobu, 1521-73), who is said to have preferred this style of guard, as it combined strength and lightness. Under the category of "Shingen", four different types abd generally listed, though a fifth appears in the drawings in the Boston Catalogue of Okabe Kakuya "Japanese Sword Guards" (p. 21). It is square, that form which is said to have been used in Ashikaga days for scaling walls, the sword having been set up as a step. [...] The following descriptions include, however, the Shingen tsuba usually met with.

1. So-called Mukade ("centipede") tsuba are made of iron in which a centepede is inlaid in brass or copper wire. Mukade tsuba of Myōchin and Umetada warkmanship have been found with the inscription, "Made to the taste of Takeda Shingen".
2. There are those of solid iron, with need centers of brass, to the edges of which is affixed a weaving of brass and copper wires which is bound to the foundation disk by a rim, usually decorated simply.
3. Another type is of solid iron, bored at intervals and laced with braided or twisted wires of copper and brass.
4. The fourth type is a chrysanthemoid form, chiselled in open work and laced or woven tightly with copper and brass wire."

I believe that my tsuba [№ TSU-0338] belongs to the fourth type. However, this particular specimen does not conform with the description of Shingen tsuba as combining strength and lightness. Its weight is 290 g, which tells us that most probably it had purely decorative function (as most tsuba in Edo period). A somewhat similar design can be found at wikimedia. A look-a-like tsuba is illustrated at Compton Collection, Part II, p.p. 26-27, №54. It is dated ca. 1700. It was in a box with Sato Kanzan inscription, and had NBTHK certificate attesttion of 'Tokubetsu Kicho'. Price realized: $5,280.

Iron tsuba of round form decorated with design of sea waves in low relief carving (kebori) and pierced with design of cherry blossom in negative silhouette (in-sukashi) and water wheel in positive silhouette (ji-sukashi). The solid portion of the plate has a shallow groove just before the edge. Copper sekigane. School attribution is unclear. Unsigned. Momoyama period, 16th - 17th century. Dimensions: Height: 70.3 mm, width: 71.1 mm, thickness at seppa-dai: 4.4 mm, at rim 4.1 mm. Provenance: Robert E. Haynes, Mark Weisman. This is what shibuiswords.com says about this tsuba:

"A very unusual iron plate tsuba. The solid plate is carved with waves on both sides. A cherry bloom in sukashi, lower left, and the right third of the plate in openwork with design of a water wheel. The rim with some iron bones. The hitsu-ana is original but the shape may have been slightly changed. One would expect this to be the work of the early Edo period, but the age of the walls of the sukashi would suggest that this is a work of the middle Muromachi period. This must be the forerunner for the Edo examples we see of this type of design." (Haynes)

I managed to find a look-a-like tsuba in Haynes Catalog #5, 1983, pp. 20-21, №44: "Typical later Heianjo brass inlay example. Ca. 1725. Ht. 7 cm., Th. 4.5 mm., $100/200". We see that the  plate design of both tsuba is the same, and the only difference is the trim. It would be logical to assume that both pieces were made at about the same time, rather than 225 years apart. To be fair, let's accept that they were made in Momoyama period.