But, I have a '71 JFK that looks just like the 65 - 69 coins (never saw a 70) I heard a rumor that some planchets did accidentally get struck with a 1971 die. It is just a rumor though, read it here somewhere.
I showed it to my coin dealer and he was interested enough to look at and weigh it. He said it was silver plated. It was a good job, done a long time ago. It has aged nicely to a dull white but I do not see any ware to uncover a clad. I am keeping it for now until I get more opinions.