These are unusual because they're tiny (hence the ruler in the picture). They're made by C. L. Wüst of Frankfurt, but the Internet doesn't seem to know exactly when. There are two packs in the British Museum that were donated in 1896, but those have patterned backs; mine have plain backs, so are probably earlier. The donated sets are likely to be a couple of decades or more earlier than 1896, come to that.
I do already have a pack of these with patterned backs that I bought 6 years ago. They're in a tiny box. This latest set is boxless, probably because they were originally in a silver box that someone decided to use for another purpose (such as melting it down). My guess is that the 7 of clubs is so filthy because it was the top card in a pile that was left for many years, which suggests that the box has been gone a long, long time.
The patterns on the card, while based on those of other Wüst patterns, seem to be unique; I can't find another Wüst deck that matches it. The aces are quite pretty — here they are enlarged.
Wüst cards are very collectable, and you can see why. I still prefer Dondorf, but I like these a lot all the same.