Dreyer's Ice Cream Porcelain Flavor board Sign

This is a 1940's or early 1950's porcelain sign that was used for ice cream parlors. They put a flavor strip across the hooks that were pressed out. The writing is embossed. I talked to a Dreyers's historian a few years ago who hasn't seen one since they were used in parlors. It is possibly the only one in existence because back in those days, Dreyers was only in the San Francisco bay area. The sign is in perfect condition. Looks like it was just made. I am looking for any comments on its history or rarity. I worked for Dreyers from 1980 to 2005 and no one has ever seen one.