It was supposed to be an Edsel, but wound up being a Mercury Comet, ca 1960. The Edsel was going kaput at the time this mockup for a "small" Edsel was being made. That's where the divided Pontiac-esque grille treatment came from. If you look at the taillights of the real 1960 Comet, you'll see a remarkable resemblance to the original Edsel taillights.
So, it's a mockup of a small Edsel, that ended up being a Mercury Comet, probably dating from early 1959 or so.
Dan