Hi Ludwigjoey. I have a Ludwig bass drum that had a hole like that in the top and I took another old drum shell, one that I could sacrifice that was the same thickness, and cut a peice out of it with a skill saw that was the same size and shape as the hole I was filling. I glued the repair piece in place and used some high strength wood filler to fill in any rough spots around it. I sanded it smooth, inside and out and it has filled in the hole nicely. I plan to cover the drum with Black Oyster Pearl and touch up the inside white paint in the near future. If you can find an old shell (same thickness of course) you could try the same thing. Good luck with your project!