Your sign is from White Star Refining from Detroit MI. The years of production for this sign were 1933-1946. According to Henderson's Guide to Gas Station Logos, "former White Star outlets used a special Mobilgas shield sign with a small blue circle and white star at the bottom until aftr WWII."

There's no stopping the Cretins from hopping
You've got to keep it beating for the hopping Cretins