12.5x17.25" flat from c. 1960. Box features So-Hi mascot on front w/text block promoting premium. Back panel has "Racing Car" offer, noting the race car (produced in a variety of colors) was issued as a box insert. Back panel also has cut-out "Start" and "Finish" flagmen. Side panel has mail-away offer for Cornelius Walking Toy premium. Unused file copy w/no folds. NM. Comes w/7-7/8x14-1/8" negative stat for mock-up ad for 1960s "Plastic-Model Racers" cereal box premiums. Mock-up features illustration of actual race cars in action w/inset image showing the premiums in use. Text at bottom notes this was to be a mail-in premium. Some scattered lt. handling wear but Exc. overall. Comes w/original 3.5" long racer vacuform plastic mold (w/o wheels), which has some scattered dust soiling but is free of any cracks. VF. Also comes w/two examples of the produced premium, in red and bue colors. Some lt. wear to blue racer, but Exc. overall. The definitive lot for this classic premium. From the archives of premium creators Sam & Gordon Gold.