The backstamp number is lucky seven. Production period: 1956-1958 (only about 3 years), making this a rare mug. There is a shallow scratch of about 1 cm in one place, but there are no cracks or chips, and it is a beautiful item with a glossy finish. This item is vintage. Due to its nature, color unevenness, clay unevenness, hairline cracks, spots, print unevenness, etc., that may occur during the manufacturing process are not mentioned. We cannot accept claims, so please refrain from purchasing if you are looking for a perfect item.