Hard to come by?

As my hands were going numb, I meet this gentleman. Conversation goes to the lens almost immediately. He stated, "It's an antique; a 197_ hand made Nikkor 8mm, true fish eye." I don't care whether or not you're into cameras, you know that's one cool fucking lens. I don't remember exactly what year it was, but it was 72-74. I asked, "So how hard are those to come by?"

"Well... I found this one in Iowa."