I have a 1939 GMC 1/2 ton Panel Truck with 2 sets of bumpers. One set has two small groves across the blade and the other set has one wider single grove approximately 7/8. Problem? Which set belongs on this truck? They both appear to be similar in length and shape and bolt up to the same brackets. And? Are panel and pick-up bumpers the same? THANKS for your input, Nick