Once it is set and hardened. I snapped off the 3/8" tab and sanded the repair. For sanding the inside areas of the honeycomb I used a plastic knife from Wendy's (they're much better than the cheap McDonalds plastic kinives) and wrapped it in sandpaper. It fit perfectly and was able to flex to fit the interior areas. Here is the finished repair:
Front view:
Rear view: