https://www.ebay.com/itm/1969-Chevrolet-Camaro-SS-396-X22/293083593907?hash=item443d24bcb3:g:CPAAAOSwrJRc1dli&vxp=mtr
Info from 2005 shows at that time it had an X11 tag and 727 interior.
I guess grinding the surface is supposed to make it look legit.
124379N701394
I have a pic of the original X11 tag - just sent it to the seller.