Well, the Chrysler Muscle Car Parts Interchange Manual says this piece for a 70 is part # 3446960, for 70 Cuda and AAR. It also says that the part for 71-4 is #3570071. Year One in its catalog sells the good repop (their #VC112) for $28.95 and says it "will function as a replacement for 1970 models with peg-style emblems."
So I don't think yours is original- no big deal, but I found holes drilled for the peg-style and would like to find an original one if possible.