I ended up with the archive of Associated station photos (several hundred) from the Portland bulk plant and although the sign is similar to one that went on the end of some canopies there are some basic differences. The canopy signs were single sided and not neon. I also have dealer mags from the 20's to the early 40's and it doesn't show up in any. It could be real, there's a lot of stuff out there that appears to be one of a kind but as said already, it's a little odd. The paint appears newer as well, assuming this was an outdoor sign.
I build signs. I would never place the glass peanuts or contacts at different locations on the wings. Any good sign builder would have done that for a more balanced and pleasing appearance. The neon tube bender wasn't very good as the bends in the tubes are different on each side when the image/graphics are the same. You think they would have drawn out a pattern and taken the time to bend the neon tube off of that. For that kinda of money, you would think more effort would have been put into it.