Original German Siemens TL3650-402 M 1 D desk lamp or Arbeitsleuchte, Schreibtisch-Werkstattlampe. This is more likely to have been seen used in workshops or general work environments for activities which require a person to be able to position the light better as opposed to simply illuminating a desk. There are many similar models with slight variations, but this particular one is the only model that I have found which was always originally a panzer gray color. The classic Bauhaus design of the lamp makes it extremely desirable within the decorator market and yes, in the lamp collecting community. There is a very healthy market of lamp people in Europe which makes the prices for these feel a bit ludicrous to me, but that is just what they cost. I get it; it is a very nice looking lamp. I did turn away many similar lamps in favor of this one due to large amount of original panzer gray.
This lamp has been rewired recently but doesn't seem to be working.
It does have some obvious patches of surface rust under the paint but the main components are original, including the switch. The only replaced component seems to be the cord. It also seems like the paint is all the original gray color.
I have another example of this lamp on my desk at home which retains most of its original panzer gray paint which is one reason I feel confident in advertising this as an actual Wehrmacht desk lamp. The standard work lamp color of the era was black so these being a distinct panzer gray color means something. There just isn't a "Lamps of the Wehrmacht" book that I am aware of with better information.