Japanese Koban-style gold-colored numismatic objects

Shown are three oval-shaped metal pieces that are stylistically consistent with Edo-period Japanese 'Koban' coinage. Each piece features a flattened, elongated oval form with a textured surface of horizontal ridges. Two of the pieces exhibit prominent cartouches containing Japanese characters including denominations like '壱両' (Ichi-ryo) and fan-shaped paulownia (kiri) seals at the top and bottom. The reverse of one piece displays several smaller circular and rectangular stamps, consistent with minting or assay marks of the period. The material appears to be a gold-toned metal, though without physical testing, it cannot be determined if these are genuine gold, plated base metal, or modern brass reproductions. One piece appears significantly more polished and reflective than the others, which show varying degrees of dark tarnish and surface patina. The variations in texture and stamping suggests these could be a mix of numismatic specimens or commemorative replicas. Such items are typically attributed to the 17th through 19th centuries or modern souvenir productions. Because these characters and seals are widely replicated for the collectors' market, identification as period-correct historical currency is a hypothesis subject to scientific metallurgical analysis and expert numismatic verification.

Based on my visual examination of these three gold-toned oval pieces, they stylistically align with Japanese Koban coinage from the Edo period. The specimens bear markings consistent with the 1-ryo denomination and feature traditional paulownia seals. However, a photograph cannot establish the metallurgical composition or the historical legitimacy of these items. I cannot determine from a photo if these are solid gold alloy, plated base metal, or modern brass reproductions; I would need an in-person physical inspection and density testing to establish the material. The the value range provided is a hypothesis based on the assumption that these could be period-correct gold specimens in varying states of preservation. The significantly polished appearance of one piece compared to the tarnished patina of the others suggests they may come from different eras or production methods. In the current numismatic market, demand for Edo-period currency remains steady among specialized collectors, particularly for examples with clear assay marks. To verify these objects, one would require scientific metallurgical analysis, weights and measurements compared against historical mint standards, and expert numismatic verification of the hand-punched stamps. If these items are determined to be modern replicas, souvenir pieces, or brass 'in the style of' Koban, their combined market value would likely drop significantly to a decorative range of $50 - $150. Consequently, this appraisal is contingent upon a professional authentication process and should not be treated as an assertion of age or origin.