Did '67 Barracudas have individual "PLYMOUTH" letter emblems on the top driver corner

If you are talking about the upper front valance panel above the grilles then....Your friend is right. 67's originally had individual letters arrayed across the panel that spelled P-L-Y-M-O-U-T-H. Each letter was mounted separately into two mounting holes.
In 68 it was a one piece emblem above the driver side head light about 6" long. It shouldn't be too hard to find photos on this site that show them.