On my 66 Barracuda the vin tag was riveted on , when I asked a police office where the other number would be stamped he told me , that it was him to know and me to find . I found some where on the web that there was a number stamped on the driver side rear bumper brace on the bottom of the brace . This brace runs from the rear of the car and welds into the frame near the rear spring shackle . Use a wire brush and clear it and see . Hope this helps .
