Exit signs - lighted deco style cast aluminum. Need info please

These signs were purchased @ a garage sale and I am very curious about any information I can obtain about them. I.E. age, value,
I have looked for hours on the net and cannot find any info or others like these signs anywhere. The backplate on the exit sign says : Osborn - Keown Electric Number Co. Culver City, Ca.
Please if anyone out ther has any info at all, about these signs. Please contact me at - juanit_at@yahoo.com
Thank you