charlie belden
I didn't drill a hole in the bottom - the tail center's in a recess in the bottom of the blank. And just above where I placed the tail center is the bottom of a large void that starts just below the surface of the top of the piece. Since the bottom is swiss cheese, even if I flattened it - there'd be very little solid surface to glue to.

I picked up some plastic beads at a recent Makers Faire that can be molded once warmed to 150 degrees. I'm thinking I could warm it up and push it into enough of the void space to create enough solid surface for a glue block to be used for the hollowing. After the hollowing is done I could heat the piece, soften the plastic and remove it. Will look into THAT possible solution.

(See, there's always a reason to buy stuff that is interesting but for which you have no specific application when you acquire it. I pick up Solutions Looking For Problems To Solve all the time - with no idea at the time what the problem it will solve might be. Done that often enough to trust my instincts.)