late production - witout "Made in GDR"... Please - Check magnet bottom of the tank... The beatifull brass tank bottom could be iron/brass platted. But what's going on? The iron/brass bottom with brass top - gives You new possibility... You have "2 in 1" - stove (may be yet) - and cu fe galvanic cell I am very sorry - Chief Engineer forgot to design the contacts... Yours 0,43 V - are not for You. But rust, willing to use it. Iron is reduced and left only a brass film. Several times used , almost new - left for a couple of years - they are good for nothing . Convey my greetings - and recall of the outstanding classes of electrochemistry.