Is There Any Value In A Souvenire From The 1939 World's Fair?

Yes, there are a lot of World Fair collectors, especially items from the World's Fairs prior to the 1950's.  You could go to ebay and type "World's Fair" in the search area and you'll see a lot of items.  Better yet would be to click on the "Advanced Search" and then check the box for "Completed items" and you'll be able to see the final auction price.  One thing to remember is that ebay is an auction and the auction price is much lower, usually, than what the item is worth.  I often buy older World's Fair items from ebay in order to sell them at a much higher price in my antique store.