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Fairly sure. The opaque ink transfer printing (possibly screen printing) makes it look a bit softer (eg edges more rounded) than the digital font. But the shapes are right. It might be Akzidenz Grotesk as the C is very round.
In any case, whether it’s Arial, Helvetica or Akzidenz those “grot” letterforms weren’t used on watch dials in the 1930s. They were metal printing types. The transfer printing used on watches was generally rendered by hand.
Are you certain it is in Helvetica? It looks similar, but not 100%.