there are always hundreds if not thousands of elephant carvings, models and such like at shrines and Wat that I visited so I assume Elephants are held in very high regard by many Thais.
I suspect that having a stuffed Elephant head in your phuket house and being so "happy" that you killed it 4 years ago is not the most appropriate social statement you could make to your prospective neighbours
Its a pity the elephant isn't still alive - maybe sell the stuff and give the cash to the World Wildlife Fund to assist other endangered species?