Well have tried to repair the rear trunk and end cap grills which are similar but have not tried the same on the front grill on a 69. For the rear I used donor material to cut out an exact fit repair and glue it in place. It can be time consuming and has to be examined from all angles before the adhesive sets up. Had a number of tries where the repair was invisible from three angles but stood out from the fourth angle. Also have to be careful about the amount of adhesive used since any additional will highlight the repair.