As the add says, 1930s German make although they seem to turn up mostly from US sellers. Clarke type rolled. I have a C, decent whistle. They aren’t extremely rare, I bought mine for a fiver and have rarely seen them go for prices much over a tenner.
Calura. Another mystery whistle, which evidently is German. I’ve seen a couple of these sold on ebay. It looks like a Clarke Original, but with rather cool and ornate livery. I doubt these are still being made. By the way, “Ornate Livery” is one of many names I’m considering for my new band. Anyway, I think these have not been made in a long time. There is a rumor that Calura was a subsidiary of Clarke.