Ford was trying to keep the Talladega Torino legend alive with the body change of 1970. I think a few of the Torinos and Cyclones had essentially the same front end. They were to compete with the Mopar Superbirds but Ford pulled out of NASCAR shortly after their introduction because NASCAR handicapped them and wouldn't let them run the Boss 429. If I remember correctly they put a few of these on the road with 428 CJ's and 429 SCJ's to qualify for NASCAR. Then again I could be completely up in the night.
Edit: Uhhh...yeah silly me, I went back and actually read the ad, initially I just looked at the picture. I think it's essentially what I was thinking. I didn't know that any of the Boss's actually hit the streets and I would expect it to truly be very rare.