if it's not too late, I use a 5/16 piece of all thread, drill up though the flat thick part where the spine hooks to the base of the skull,(between the two bumps), slip the all thread up through the hole, and put a nut on it inside the brain cavity, and one on the bottom of the skull, trim the all thead long enough to reach through your board for a nut to hold it on the back side,,,,one other idea is to cover the bottomof the teeth with a thin coat of hot glue where the teeth meet the plaque,,, this will keep them from scratching the wood... also fill the brain cavity with paper mache after you get the bolt in. this will seal off that area from critters wanting a new home.
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