(x) type printed on WW II era US Army boxes - Copperplate Gothic {Akira}

I need to know the font that is printed on the boxes in the attached photo. Can anyone help? It's not Bell, which was my first thought. There is some variation in the letter strokes, it is definitely a serif. The printing is period-accurate, so whatever it is was (a) around in the early 1940s, and (b) used by the US military.


I think it’s Copperplate Gothic

Copperplate looks the winner; I should have noticed the little serif flanges, that's a dead giveaway. Thanks akira.