We have had gatorboard routed by Harbor Sales and then applied the graphic, we printed the graphic with a 1/4" outline apply transfer tape to the graphic, make a loose trim around the graphic thru the transfer tape, graphic and backing
paper, aline the graphic over the gatorboard cutout, tape it in place then remove the packing
paper from half the graphic, apply that half then the other half and trim the excess to the perimeter. We have also applied graphics to uncut gator an then trimmed the gator to the contour with knife or jig saw. Depending on the detail of the contour, cutting gator can be tough. We have recently started using Ultraboard, which has styrene surfaces and is a lot easier to cut.