I can't find any info on these being used by the military during the war. This 1939 survived. Just a great looking truck. Having obtained production equipment bought from the American company Graham Page in 1937, the company started production of a large vehicle - the "NISSAN". The powerful 3,670cc, 85PS, 6-cylinder engine and Japan's first semi-cabover design together made this a popular vehicle. This particular vehicle was used by the Mitsukoshi department store through the war years, from 1939 till 1965, to make deliveries. Nissan | Heritage Collection | NISSAN Van
Did you see this story on there about it being restored ? [REPORT from NTC] Skill Olympics expertise and youthful passion resurrect the 1937 Nissan van (Type 80) | Nissan Heritage Collection
Hadn't seen that article. Thanks. I assumed they were using a Chevy based OHV 6 like their cars did but I see a flathead 6 in the article.
Searched in Japanese & found these photos of it...and loads more NISSAN Mitsukoshi 日産 三越 『★1937年 戦前のニッサン80型ト…』 デイズとeKワゴンの内外装の違い https://nissangallery.jp/wp-content/uploads/2014/08/20140729_ghq_162.jpg and http://blog-imgs-51.fc2.com/b/a/l/bal4s/fc2blog_20141116113116b58.jpg
I see Graham Page was associated with Dodge for a while. Might be Dodge flathead tooling. Chrysler flathead engine - Wikipedia