Hey Fred
I follow signs, tobacco card related, just a little bit. I will make some guesses from what I have seen and if there is an expert that knows the absolute answers, he or she can correct me. I think the sign is from the early 1900s (to about 1930'ish) and the value, if in nice shape and porcelain, should be in the $100-$200 value range. I have seen some more elaborate ones which I think would go for more. If it is double sided it will be worth more. I've seen quite a few different varieties with all of them being blue with white lettering (that I can remember). There are vintage chairs with the same designs. Hopefully they aren't made out of porcelain too.
Hope this helps a little bit. BTW, ebay or an AH would be a good place to sell (or our BST
) if he wants to go the sales route.