I live on a farm in Illinois and found these two signs a few years back.  I am familiar with the one on the left, but don't know much about the one on the right.  I'm assuming NMA is the National Motorists Association and I'm betting this was a sign around during the fuel and oil rationing of WWII.  I'm primarily concerned with value as I am not a sign collector and may end up trading some signs for some debt on a tractor.  I know it comes across as crass to basically ask "Whats it worth" as I know that depends on so many things, but I need a ballpark on its rarity and possible worth.  I don't want to get taken in a deal.

I have found zero information on this sign online, on ebay's completed listings, or anywhere to be exact....which is sometimes a good sign (nice pun!)...It's about 27 inches long, is double sided, and is in very good shape on both sides as it was probably only up outside for a few years and then stored in the rafters of a shed for the last 60 years.

Any help you can give me would be much appreciated!

 From over the pond I can't tell you anything about the NMA sign as it is not one that I have seen before or one that I would put in my collection. I do have one of the Goodrich post mount signs in my collection and from memory I paid $125 US for that one. I hope this is of help to you.