Rare and complete technical supply box from the Imperial Japanese Army, used to store spare parts and accessories for a field petroleum-powered air compressor, Type AC (石油空気圧縮ポンプ). The lid bears large stenciled kanji identifying the unit type. Inside the lid, an original Japanese parts layout diagram (配置表) on period paper is nailed in place, listing every component with its storage position — remarkably intact. Original wooden interior brackets/holders survive. Iron hinges and latches function. A penciled inscription “D.R. Vander Meer” identifies the American soldier who captured and brought home this item from the Pacific Theater. An exceptional research and display piece with full provenance.