Hi, I would estimate a date in the 1930s for your stove. Have a look at this thread: https://classiccampstoves.com/threads/juwel-21-pair-comparison.32301/ And here are instructions and parts list : https://classiccampstoves.com/threads/1930s-juwel-general-instruction-parts.149/ Best Regards, Kerophile
This is an interesting example. I think it dates between my 2 examples in my Juwel 21 comparison link above. It has the fill cap placement and stampings same as my fixed leg 21 while having the folding legs and reserve cap on the pump handle as my later model does. Can you post a picture of the top of the carry tin and close up of the burner top?