I believe this piece by Heinrich Kley was offered on Ebay a while ago. And it sold for a lot!
But for all the right reasons, as this really is a magnificent drawing.
Kley used to occasionally copy his own drawings for fans who loved the unavailable original.
But a re-drawn sketch never has the vitality of the first version.
This one IS the first version! You can see lines that search for perfect anatomy and composition.
One of my all time favorite Kley illustrations.