I also thought of something else that you can do. Call Hershey's 800 number and ask to talk to someone in consumer affairs. Explain what recipe you are looking with as much detail as you can--describe the candy, the era, the look of the packaging etc. and see if they can locate the recipe for you. I have done that in the past for my mom with Quaker Oats with great success.
Go to Contact Us - HERSHEY'S
Hershey's: 1-800-468-1714 Mon thru Fri 9am to 4pm Eastern Standard time.