I discovered this photo of a 1:1 scale maquette of the Dino GT4 in a book recently, and was quite excited, as I had never seen this photo before. It's interesting to note the more flamboyant treatments of the air intakes and outlets when compared to the more restrained final design. Gandini also did well by adding the additional character line along the flank of the final car to break up the vertical mass of the body. That line is absent on this early study. The elegant and subtle hood creases on the final car are also not yet defined on the unadorned nose area.
The production rear end treatment and bumpers are also far more delightful and nuanced than this maquette, meaning, I would assume, that this is one of the earliest full scale models made. Note that the maquette is described as a clay model, but I believe that Bertone and the other Italian design houses worked primarily in plaster models at the time, with clay being more prevalent in Detroit.