You can look on the back of it first.. most reprints are stamped as such somewhere with the date. if there is nothing there you will have to have someone knowledgeable check it out.
My Grandfather started a JD Dealership here in this small town when he came back from WW2, so my parents have quite a few old prints. Unfortunately, while I was away in the Navy JD decided to close down all dealerships that were not in the county seats.. so despite having the highest sales and satisfaction rating in the state.. the family business was closed.