My new old lamp....

Got this on eBay for $6. It came in today, I cleaned it up and put in a new socket. I love the way it looks. It reminds me of the front of an old car or truck. I have two other old lamps like this, but this is the first I've seen with this type of shade.

Any idea how old it might be? The only markings are the number 26 and the number 1 on the base.

Thanks!