I haven’t come across that craft before. The picture seems to raise more questions than it answers, but anyway, a craft that size would be massively overpowered by a Griffon quite apart from incurring a massive weight penalty. Most likely there is no connection with the Griffon, but considering the unusual features (does it have a skirt, how high is the CG, what cargo space is there, what road wheels did it have, what road propulsion was proposed, how fast was it intended to go, etc), who knows? The mention of a cushion/road hybrid suggests a 1960s experiment of which there were one or two.