The piece, Untitled (Travelling Dreaming) by acclaimed artist Mick Namarari Tjapaltjarri, is estimated to be worth up to A$150,000 (US$110,000; £90,000) and was the subject of extensive searches after its disappearance 35 years ago, the ABC news website reports. Often referred to as a Papunya board , it was loaned to the NT Chief Minister's Office in the late 1970s, and that's where it was last seen.