In addition to the new rear step side fenders that should have come with the 1960 models, I was always disappointed they never came up with a transitional hood for the 1962 model either. My concept would have been to keep the original drop center blended with the smooth corners from the later hood. This is a crude photo chop using my truck and a 1959 Oldsmobile hood in the center. Unfortunately I don't have the skills to pull it off in metal, but I may do it in fiberglass someday:
I would imagine by this time at GM all the designers were already working on the 67 models and had little interest in making additional improvements on the old trucks.