Its not difficult to make a billet style grill for early stangs because the shape is quite simple. Just takes a little patience, here is a pic of my stainless steel grill.
I made one friday from 35$ worth of stuff I bought from Lowe's. It looks every bit as good as the one from Cal-Mustang. I made 16 grille bars, spaced out just a little less than half of an inch from each other. They are spaced exactly like the factory 68 grille. I will put pics up here after I borrow my GF's camera.