This is an unusual Wisconsin Division American Automobile Association “dangler” sign. It's from the late 1930’s-early 1940’s. It is a two-sided porcelain AAA sign. It includes the original decorative iron hanging bracket.
Obvious, what makes it special is the Wisconsin personalization, the “Official Service Station” reference, and the dangling configuration. The top rectangle sign measures 22-1/2” by 5-1/2”. while the bottom oval sign is 22-1/2” by 16-3/4”. The overall condition is decent. Some surface rust here and there, as shown. reasonably good color and gloss. Both sides are equal quality. I believe the outer perimeter of the sign will clean up further, (using Barkeeper’s Friend). I spent about an hour cleaning this piece already, and kind of ran out of steam.
This is a sign I personally removed and purchased from a near-by, small town Chevrolet dealer (now long gone). This was in the early 1980’s. The sign had been on one of their outside walls for years.
The price is $1,575, plus the shipping.