Barris used Lucite rods and painted stars to good effect on this one. (Zoom in.) Another using Lucite with mesh. Quad lights were also the rage, when drawer pulls became popular. There are some creative grilles on the "Canted Quads" thread HERE: http://www.jalopyjournal.com/forum/showthread.php?t=415441&highlight=canted+quads If you can find them, '58 Ford mesh with Cadillac bullets makes a great combo. (post #117 in above link). Ray Fahrner also used this combo, in the 'Eclipse'. The 'Mountain Pear' is one of my favorites.
A Vette grille fits the T-Bird bumper nicely, as on this one by Dick Jackson. (Could use 2 more teeth.) FWIW, I think your car looks good already.
Remember tube grills were popular in the early 60's too! The car in question was mine and I have a grill like the tbird pictured in this thread for it too.
A bullet grille is another option. Similar to the drawer knob grille, bullets look especially nice in large openings like yours. I believe Gene Winfield still sells these bullets in multiple sizes. I photochopped some in your car to give you an idea.