Gift Cufflinks from the Kan'in-no-Miya Imperial Family/皇族御下賜品 閑院宮家 カフスボタン

Marked with manufacturer mark and 銀 - silver.

Original case.

 

Marked M inside the shell for Mikimoto workshop https://asiamedals.info/threads/history-marks-and-products-of-mikimoto-workshop.19773/ and 銀 - silver.

Original case.