This little coin is 15mm in diameter. It was minted in San Francisco for the Dutch East Indies (now Indonesia), but never circulated as the Japanese controlled the islands. Probably some US serviceman picked up the coin in Asia and brought it back to the US, where it ended up in San Francisco, and where I bought it sometime in the 1960's.
I should say it probably did not circulate in 1942, but did in 1945 after the Japanese left the East Indies. I do not think that the Germans were ever in these islands. I got it in the 1960's and probably paid 10¢ or 25¢ for it.
Well, some Germans undoubtedly visited the islands while they were ruled by the Dutch. The Germans occupied The Netherlands during WWII, but the Japanese occupied the territory that is now Indonesia. At least, that's how I remember it, and what all the historical references Google can find say. The Dutch East Indies were, after all, in the Pacific near Asia, not in European waters.