As for today the exact owner of this mark remains unknown. Presumably mark was used by Namikawa Yasuyuki /katakana ナ reads Na/. Unfortunately, at present this hypothesis cannot be conclusively proved.
From 1906, Namikawa was also involved in the manufacturing of medals and orders for the Awards and Decorations Bureau.
After the Meiji era, foreign demand for Japanese art tailed off. Namikawa Yasuyuki retired in 1919 and his workshop closed in 1923.
Namikawa Yasuyuki with a Green Ribbon Medal of Honour https://asiamedals.info/forums/green-ribbon-medal-of-honour.818/
Namikawa Yasuyuki workshop (Yasuyuki Namikawa standing at the back right corner).
Standard mark of Namikawa Yasuyuki workshop that was used on cloisonne items (cases, bonbonnieres, etc).
京都並河 = 京都 (Kyoto) 並河 (Namikawa)
Workshop that used this mark was active during the first quarter of the XX century https://asiamedals.info/threads/time-coordinates-of-mark-na-on-japanese-orders-and-medals.25149/.
Namikawa Yasuyuki (並河 靖之; October 1, 1845 - May 24, 1927) was a famous Japanese cloisonné artist. His work was highly sought after in his own lifetime and is held in several collections today. He and Namikawa Sōsuke (濤川惣助; April 1847 - February 9, 1910) (no relation to Namikawa Yasuyuki https://asiamedals.info/threads/green-ribbon-medal-of-honour-document-issued-in-1895.28709/) were the most famous cloisonné artists of the 1890 to 1910 period, known as the "Golden age" of Japanese enamels. From 1875 to 1915, he won prizes at 51 exhibitions, including at world's fairs and at Japan's National Industrial Exhibition. For his work he was appointed an Imperial Household Artist in 1896. He sometimes signed his pieces Kyoto Namikawa (Namikawa of Kyoto).
A former samurai, Namikawa Yasuyuki started work as an artist around 1868, working for the Kyoto Cloisonné Company from 1871 to 1874 and eventually forming his own company. Along with Namikawa Sōsuke, he was one of only two cloisonné artists ever to be appointed Imperial Household Artist. These artists were given a yearly stipend and were commissioned by the Imperial family to make presentation wares as gifts for foreign dignitaries.Namikawa Yasuyuki (並河 靖之; October 1, 1845 - May 24, 1927) was a famous Japanese cloisonné artist. His work was highly sought after in his own lifetime and is held in several collections today. He and Namikawa Sōsuke (濤川惣助; April 1847 - February 9, 1910) (no relation to Namikawa Yasuyuki https://asiamedals.info/threads/green-ribbon-medal-of-honour-document-issued-in-1895.28709/) were the most famous cloisonné artists of the 1890 to 1910 period, known as the "Golden age" of Japanese enamels. From 1875 to 1915, he won prizes at 51 exhibitions, including at world's fairs and at Japan's National Industrial Exhibition. For his work he was appointed an Imperial Household Artist in 1896. He sometimes signed his pieces Kyoto Namikawa (Namikawa of Kyoto).
From 1906, Namikawa was also involved in the manufacturing of medals and orders for the Awards and Decorations Bureau.
After the Meiji era, foreign demand for Japanese art tailed off. Namikawa Yasuyuki retired in 1919 and his workshop closed in 1923.
Namikawa Yasuyuki with a Green Ribbon Medal of Honour https://asiamedals.info/forums/green-ribbon-medal-of-honour.818/
Namikawa Yasuyuki workshop (Yasuyuki Namikawa standing at the back right corner).
Standard mark of Namikawa Yasuyuki workshop that was used on cloisonne items (cases, bonbonnieres, etc).
京都並河 = 京都 (Kyoto) 並河 (Namikawa)