Probably off the shelf Phantoms or Mirage 3s, depending on the agreed all-up weight. My guess is Micky D would push a single-seat Phantom as the US entry, then decide that the major modifications would cost too much. Then the French will buy Mirages, the Brits will make Phantoms with RR engines they will sell to the Benelux countries, Norway and Sweden will buy Drakens, and the Germans for some reason will buy Phantoms with Atar engines.