Rare Vintage pabst blue ribbon pub sign

I was given this sign as a christmas gift from my sister. Her boyfriends father was a beer distributer back in the 1940's. He had two of these signs that he says have been in the family for 75 years. They have never been hung or dispayed. They have minor scuff marks from being stored in a box with other stuff. Does anybody have any information on these signs or can the age be determined by the advertising? Ive only been able to find one other that sold last year on ebay. It was well used and rusty.