Found in at attic in 1974

My dad found this lamp in the attic of an old abandoned house in 1974. Thats it! Thats all i know about it. Need help in finding its origin. Only markings i see r on the bottom it is stamped w-85, im not sure of the first letter or number after the hyphen,but to me it looks like it could be an 8, 5 or even an s. The last marking though is the number 5. HELP NEEDED IN FINDING ITS ORIGIN AND VALUE!