While you have this one already apart, you have time to play with the size of the center hole. Make a plug to fill the hole, with a lip on it, sort of like a very short bolt with a round head. Not sure on the size you drilled it, but let's say you drilled it an inch wide. First glue the call back together, drill the plug with a size smaller than your regular size, then fill the hole. Test the sound, TAKE NOTES, then pull the plug out and drill a size larger and do the play it again. Try this for over and over and take notes on how the hole affects the sound. Then when you have what you think is the best, make another plug with out the round handle and with the correct sized hole to glue in place.
This isn't a perfect test method, because a solid piece of wood glued in the hole and a plug that is not glued in will not be the same, but it will be better than trashing it and never knowing the "What ifs I had changed the size of the hole". You can do the same thing with all of the holes, but it sounds like you are very close to the sound you want, so save the other holes for later testing.
Marvin