[Eliot Ness]

You might need to find a thin piece of material to use as a backing plate to glue all the pieces to and then glue to the rest of the grille. If it is thin enough and trimmed smaller than the grille bar it should not be very noticeable.

A last ditch alternative might be trying to find something to replace that bar with. I'm thinking you find a flat piece of chrome about the same thickness and cut it to shape. The trick is finding a flat piece of chrome that same thickness that will match the patina of the original grill.