A very large and very thin iron tsuba of round form decorated with design of formalized butterfly and dragonfly in openwork (sukashi). The characteristics of the plate resemble those of Kamakura period ko-tōshō tsuba. However, the design seems too 'modern' to me, but it's hard to tell; it may be a late Muromachi or Momoyama period work. Tōshō or Ko-Tōshō school (or a Katchushi). Muromachi period. However, Boris Markhasin and Skip Holbrook insist this is a 20th-century machine-made tsuba. Dimensions: 99.6 x 100.5 x 2.1 mm. This is what Jim Gilbert says about old tsuba:

"Traditionally the old iron plate tsuba are classified into Ko Tosho (old sword smith), and Ko Katchushi (old armor maker) styles. It is sometimes difficult to justify attribution of a given tsuba to the Tosho or Katchushi category. Generally guards with raised rims or relatively complex designs tend to be assigned to Katchushi. This is basically a convention we follow out of habit and convenience." [...] "In Token Kai-Shi part six, Articles by Akiyama Kyusaku, Robert Haynes comments: "…from 1300 to 1400 over 150,000 MOUNTED swords were made in Japan for export alone. This means that over four tsuba a day were made for 100 years. This would mean that at least 3000 persons were making nothing but tsuba, let alone all the other fittings needed to complete these swords. With sword smiths, fittings makers and all the other artists need to complete a sword for export, at least 10,000 sword artists were working together, in any one of these hundred years."

Another tsuba of similar design, Tōshō school, is illustrated in this collection; see TSU-0319.2015. Reference to this design can be found in LIB-1359.2017 Japanese Swords and Tsuba from the Professor A. Z. Freeman and the Phyllis Sharpe Memorial collections, Sotheby's, London, Thursday 10 April 1997; p. 18-19, lot № 37: "A Kamakura-bori Tsuba, Momoyama Period. ...pierced with two large formalised butterflies..."  

Two ymagane tsuba (daisho) with chiseled diaper pattern of waves. The larger tsuba (dai) is of mokkō form with a wide (4.6 mm) polished rim (fukurin?). Water spray is realized in copper ten-zōgan. Size: 75.0 x 71.6  x 3.2 (center), 4.0 (rim) mm. Copper sekigane. The smaller tsuba (sho) is of oval form, without a rim. No inlay. Size: 53.2 x 45.5 x 4.1 mm. Ko-kinko school. Muromachi period. In Kokusai Tosogu Kai; 5th International Convention & Exhibition, 2009 on page 51 under № 5-U8 there is a piece from George Gaucys collection, described as follows: Unsigned Tachi-Kanagushi tsuba, Yamagane base. Nami (wave) motif. Circa: Muromachi period (15th century). 6.88 x 6.81 x 0.45 (rim), 0.36 (center). The classic wave form is typically seen in Muromachi period tosogu. The patina is rich and rustic, which presents history and warmth. This tsuba may be interpreted as either tachi-kanagushi or ko-kinko work. Early tachi tsuba were symmetrical in design and also not very sophisticated, Design elements filled in up to seppadai as the waves do in this tsuba. There is a simple fikurin of the same metal and it is flat to the plate. On the ko-kinko side, the crests of the waves show more complexity than tachi works and less symmetry. A very intriguing tsuba from late Muromachi period."

Circular form tsuba made by a mirror-maker, i.e. kagamishi. Cast yamagane plate with design of six persimmons on their peduncles surrounded by leaves. Slightly raised rounded square rim. Hitsu-ana is brutally cut later in time. Copper sekigane. Early Muromachi period (1393-1457) or earlier. The inscription on the box reads: "Kamakura or Muromachi Period. Yamagane Tsuba". Dimensions: 81.9 x 81.6 mm; thickness at seppa-dai 2.8 - 3.0 mm, rim 3.4 mm.

Iron tsuba of four-lobbed mokkō form decorated in brass and shakudō inlay on the face with design of rotten skull, fly, maple leaf, pine cones and needles, and on the back with design of rotten skull, wild boar, pine cones and needles. Scattered brass dots on both sides. Hitsu-ana possibly cut off later. Surface has traces of lacquer (urushi). Momoyama period. Dimensions: 67.3 x 61.5 x 4.3 mm A similar example can be found at Tsuba Kanshoki by Kazutaro Torogoye, 1975 on p. 61: "Heianjōzōgan tsuba. No sig. Iron: Pine-cone, seeds, ants & rock, brass zōgan. Kakumimi: C. 1.5 bu. Age: Momoyama. Sup. - Early work. Interest."

Iron tsuba of round form represents an eight-spoke Wheel-of-the-Law and in the same time (because of the inner shape of cut-outs) - a sixteen-petal imperial chrysanthemum in openwork (sukashi). Decorated on both sides with vines, leaves, and tendrils in suemon-zōgan and sen-zōgan. Spokes and hitsu-ana decorated with rope-like linear brass inlay (nawame-zōgan). A somewhat look-a-like tsuba is referenced in Gary D. Murtha's Japanese Sword Guards. Onin-Heianjo-Yoshiro book on page 61. Mr. Murtha attributes his piece to Heianjo school of Azuchi-Momoyama or early Edo period. However, tsuba in this collection looks older and bolder than the one in his book. It is larger (84 mm vs. his 66 mm), the spokes are longer, the inlay is of better quality, it is relatively thin, with deep black patina, and with the traces of lacquer (urushi). This may indicate that this tsuba belongs to Ōnin school and dates at least to late Muromachi period, ca. 1550, if not 1450 AD. Mid to late Muromachi period (ca. 1450-1550). Dimensions: 84.3 x 83.2 x 3.2 mm "In Japan, the Wheel-of-the-Law is an attribute of such deities as  Senju Kannon, the Thousand-Armed Kannon, and Dainichi Nyorai, the principal deity of Shingon Buddhism [Merrily Baird]. May be used as a family crest (mon).  

Ko-kinko ymagane cast tsuba of mokko form (kirikomi-mokkō-gata) with chiseled diaper pattern of double head waves on both sides and a rabbit cast and carved with its eye inlaid in yellow metal (gold or brass) on the face. Fukurin which holds together the sandwiched layers of metal (sanmai) is about 2.4 mm wide. A look-a-like tsub of oval form instead of mokko-gata  is illustrated at Robert E. Haynes's Catalog #3,1982 on page 11, lot 15: "Rare design in style of Sanmai (three layers) / Wasei work. With yamagane core and heavy rim cover. The web plates are carved with double head Goto style waves and the face has a fox. The web plates were riveted at the seppadai.  See Lot 4, page 8. Ca. 1350. Ht. 6.6 cm, th. 3 mm" [underscore mine]. Quality of photo is so poor that I decided not to provide it here. Muromachi (if we follow Robert) or Momoyama period. The Momoyama attribution is mostly based on a fact that "waves and rabbit" motif became most popular in Momoyama times. Size: 68.5 x 59.8 x 4.0 mm. NBTHK Certificate № 423120. This tsuba is listed at Yakiba website with the following passage: "Attributions as well as dating of this type of tsuba has been the subject debate over the years. There are those who believe these type of tsuba to be ko-Mino (early Mino School) tsuba, others believe them to be tachi-kanaguchi tsuba. Still others insist they are simply ko-kinko (early soft metal) tsuba. This tsuba was authenticated and determined to be "Ko-Kinko" by the NBTHK". Oval form tsuba with the same design can be found in this collection - TSU-0323.