The blue globe is not original to the lantern, although it is quite old. The burner cone has the words 'PATENTED' embossed on the top and the burner, itself, has some remaining original red paint still remaining on the underside of the burner.
*The BAT 200 model was produced after the war in the GDR (German Democratic Republic)
from 1960 to 1965. It was a joint production with the factory BAT in Beierfeld, who manufactured the fuel tank and FROWO from Beierfeld. The Burner was made by Frowo. *Thank you Achim for this information.
The dark spots you are seeing is where the tinning has minimal loss, but overall, this is an excellent example of a Bat 200 and quite rare to find in this condition.