A Very Rare German-Japanese NSFK Badge in Silver with Case

Badge in silver, die struck with polished highlights and very crisp details, 43.67mm x 51.6mm, it weighs 32.9 grams, depicting NSFK symbol, below Japanese and German National symbols, all characters in Japanese script, reverse unmarked, very high quality badge in near mint condition; in large black case of issue, also with Japanese characters inside of a lid, hinge delicate; an extremely rare badge, possibly given for a Japanese/German flying championship meeting during the 1930’s.