CLIFFORD F111 AND THE REVELL F111 TFX ORIGINAL BOX ART

The other day I posted a picture of the 1960's plastic CLIFFORD F111 swing wing jet currently for sale on Ebay by Skippyromeo. Keen-eyed reader Spectrum Steve has sent in an excellent picture of the orginal REVELL 1960's boxart for the own F111 or TFX. They are clearly the same! Would Clifford have sought permission to do this do you think? Revell boxart is well-loved and well-documented on sites like the Box Art Den (anyone know who this artist is?). Did they licence the art to Clifford? Both pictures appear below for comparison. Spectrum's Steve observes:

"Woodsy, as promised in my comment, here is the box art for the Revell 60's issue of the F-111 or as it was know at the time, the TFX. As I also said, the American Secretary of Defense at the time, Robert McNamara, had wanted the U.S. Navy and Air Force to use the same aircraft in order to cut costs hence the different markings on the box art (and in the kit....if my aging memory serves me well!) The kit was really well done with operating wings and undercarriage and if once again memory serves the unique ejection mechanism which turned the entire cockpit into an escape pod in an almost SF sense. Hope this is of interest! Spectrum Steve."

pictures courtesy of Ferryman (top) and Spectrum Steve (bottom). Thanks for sharing.