Just finished with an Optimus 1200. The first model stamped 200 on the tank. The lamp started and burned well on the first try. Have been looking for this model for a while, is not very common. The lamp was converted to alcohol but I changed it back to kerosene. Spirits Conversion Kit
Thanks! It appeared on Facebook for sale. Bad picture but saw the double knobs. Asked the seller if it was a 1200 but he replied that it was written 200 on the tank. The heart rate increased.
They existed in 1940 because they are listed in a catalogue for that year, but I believe they could have started a year or two before.