Does the Balloon Tire illustration date this sign to the 20s or 30s? I got a good deal on this, and I like the illustration, but I am really hoping to find one that says "Air Cooled Tires" on it. I started looking into the Seiberling brand when I was researching the history of my old tire store Diamond T. When I saw their "air cooled" slogan, I thought one of those signs might make a nice gift for my Dad because of his air cooled cars.
Looks more like a 1930's sign. I know they can go as high as $900 if not more in almost perfect condition.
The sign must be pre 1940, because the company changed their slogan in 1940. If it is porcelain, that would probably make it older than painted or screen printed.