https://www.thedrive.com/the-war-zone/the-beach-bum-has-flown-west-jimmy-buffetts-legacy-in-the-sky
My brother helped introduce him to Grumman Goose flying, and my brother's very close friend sold him the Goose that he owned until fairly recently.
From the FAA database, it looks like the PC-12 and the Caravan were the only airplanes he owned at the time of his death.