Verifying & Dating a Nessen Lamp  

Good Evening,
I obtained a lamp from an estate sale and after some research I am fairly certain I have a Walter Von Nessen Lamp.
What I do not know is the age of it, or have absolute certainty that it is a Lamp by Walter Von Nessen.
There is a Nessen lamp that has an identical sphere generally in the design and the legs are identical as well the brass connector attaching the 3 legs to the sphere, the differences are however that my lamp has a decorative feature above the sphere, my sphere also has a brass scallop decorative feature and there is no ring at the base. I do note the Nessen lamps with the ring have the legs slightly in more as a ring on my model would be impractical.
I am inclined to consider it could be an earlier piece as it seems to have Art Deco features and not as modern as the similar Nessen lamp done in the 40's.
Since obtaining it, I changed out the socket which was burned out, and it previously operated by a switch - I changed it to socket with a pull chain.
The lamp shade photographed is what came with it - it is fabric on the outside and paper on the inside, no plastic.
I would be interested in any positive or informative input from persons who are familiar with Walter Von Nessen and know his work.
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