United States Savings Stamps Sign

Just got back today from a trip up home to PA. Of course I had to go junkin' while I was up there. Got this fantastic United States Savings Stamps sign in great condition. Unfortunately, the wording on the bottom, right corner got hit by the rust bug. I've been looking online but can't find much about this sign. I've seen one other one but a different design that said they're from the WWII era. Anyone know for sure when it might be from? Measures 3 ft. by 4 ft.