So you have two that are completely smooth?
That's not uncommon, some people like to use the smooth ones for the top and bottom and use a 71/72 bumper (turn signals in the bumper) or mount custom turn signals hidden behind a billet grille or something (like the first pic you posted).
I don't think I've ever seen them reproduced. It's only been in the past couple years they started making the outer grille shell for the 67/68 trucks.
You can kinda see the difference here. The lower one is "indented" flat on the ends for the park/turn signal lights to mount to:
