I saw that thing. I THINK it is another make, Chevrolet possibly (solid wheels)? with a Ford emblem on the radiator with some other modifications. Looks like model T fenders. This is just my opinion. I saw it and was pretty infactuated with what it could be...and eventually gave up.
The box is studio made I'm pretty sure. Interesting that the type on the box doesn't match up with their 'studio' picture (one has serifs (little feet on the letters) and the other is san-serif (without the little feet)). Anyway, if it was used in the movie, which is probably was, then the lettering looks to have been repainted. Pretty cool old truck, whatever it is.