I have not really been able to track this one down and have not found any reference to Supremus. (I’m sure someone here will be able to.) The only marking, apart from “Supremus No 1”, is “Made in Danzig” and this could mean that it was produced somewhere between 1920 and 1939 in the Free City of Danzig. Stefan
I saw “Supremus No 1” “Supremus No 1” WITHOUT ANY OTHER writings. It means - production was before 1920 or after 1939, too
Possibly the "Supremus" could have been manufactured in the Optimus factory joint venture in Danzig, see a more elaborated explanation here: https://classiccampstoves.com/threa...ped-optimus-original.33700/page-2#post-415956