Couple other things you can do here. One is to measure the location of the holes from known points on your cab before installing the headliner, then remeasure the hole locations on the headliner after installed.
OR
Before you install your headliner, take a piece of paper and make your own template. If your finger or thumb is not quite clean, when you rub over the holes on your paper, it will leave a silhouette of the hole. Install headliner, transfer holes, etc.
