That's a 47, and 48 GMC 1/2 to-1 ton grille. It isn't missing anything. They only have the three horizontal bars, on those two years. 49-55.1 have four bars. Left pic. shows 47/48 3 bar grille, and right pic., shows 49-55.1 4 bar grille.
Spanky Hardy Collector Of Fine Old G.M. COE Trucks & Antique Holmes Wreckers