I have the darker/maroon color version on my car and would like to share a little information. I took some photos recently of an original and a reproduction. On the front side they are very similar in most respects and and very hard to tell apart. The OE emblem, on the left, is just slightly lighter in color/hue and the chrome around the lettering is brighter. The original has better casting definition, the colored outer border is thinner, the GT letters are slightly more elevated and the emblem is a little heavier.
On the backside of the original the casting differences are obvious.The original, on the left, the upper left rectangular pad is stamped with the part # C5ZB-16098-G. The upper right rectangular pad contains the stylized FoMoCo and oval. Near the bottom is stamped AECo. Brian