I have a dash with factory cutouts and plan to use Autometer's classic gauge sets. The Tach and Speedo, are to large to fit in the pre-cut holes. If the holes are expanded to the larger stamped size, ithe dash holes will be to large to catch the entire gauge bezel. I don't plan on using a dash pad, just the vinyl covering, so dash hole size is be more critical. What is the secret to getting the right sized dash hole?