See also https://asiamedals.info/threads/army-aviation-maintenance-school-25th-class-of-engine-mechanics-graduation-commemorative-watch-fob.27626/ ; https://asiamedals.info/threads/1942-army-aviation-maintenance-school-26th-class-of-engine-mechanics-graduation-commemorative-watch-fob-1942.27774/...
1940年第81期撃爆操縦學生記念章
1940年第八十一期撃爆操縦學生記念章
81st class of army bomber pilots watchfobimperialjapanesearmyaviationschool badge
imperialjapanesearmyaviationschoolwatchfobjapaneseaviationwatchfob
皇元二千六百年第八十一期撃爆操縦學生記念章