Shakudo menuki signed "Hirotsugu" with Kao. There where few artists that used that name. Based on Kao and similarities between this menuki and piece made by Motohiro, I think it was made by Shokatei Hirotsugu from Kyoto. He was active around 1850. His master was Motohiro who learned from Otsuki Mitsutoki and Mitsuyoshi.
This menuki are superb when it comes to craftsmanship. Made of shkuado with inlaid copper, shibuichi and gold.
Made around 1850.
1: 35 mm x 15 mm x 8 mm
2: 36 mm x 15 mm x 8 mm