HARRY - It gets complicated. But brand & model decals were created with marketing input. Some decals were legally required like the patent decals and warning decals. Then engineering wanted decals highlighting service points, like the grease zerk on the frt of the driveshaft on the '61 to '63 CC's. All those decals were drawn, artwork approved, sourced, added to bills of material, and costs added to the machine.
BUT then the plant wanted to reduce the cost of production as much as possible, but still build a marketable product. For the most part, IH plants didn't really have "drawing control", Hinsdale Engineering did... Hinsdale didn't care HOW the machines got built... just as long as they were built correctly....The plants had to create the processes to build the machines efficiently.
As the CC models evolved over the years, more decals were used and the decals had mulitple colors, read "more expensive". Marketing was winning the battle of "More is better". On the large FARMALL tractors, decals were replaced with stamped metal emblems for name & model identification... VERY expensive, then they went back to decals in the late 1970's.
It all depends on "percieved value", what a customer is willing to pay for. Simple marketing 101.