Both of them look like a decal applied over the top of a conventional 12 hour dial. Both watches have had the exact same decal applied. I would guess that it was an after-market addition. Whenever it was done it looks like it was a long time ago, perhaps when the watches were near new. Perhaps it was for some official purpose e.g. the decal was available for military officers who wanted 24 hour time marked on their personal watch.
Agreed, those are seen pretty often in Europe, rarely (or so it seems) on American listings. Interestingly, some American made watches sold here in Poland also have this feature applied. So likely it was a modification offered by various places in earlt 20th Century... A dial mod one could say today
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