It seems like '63 C-50 and larger trucks got a '62 Grille for some reason. The larger trucks also don't have the mesh in the grille like a pick-up has. The grille looks like the correct one to me.
Also want to point out that the truck should be a "C" series.
If original, the engine should be a 292, but if you get the engine code on the pad next to the distributor for us, we can verify what you have.
Nice truck by the way. You sure got a good deal.
Bill