The P-2 Neptune was a long range maritime patrol bomber and ASW aircraft that first flew in 1945 and served in that role until 1984. The P-2 was mainly used by the U.S. Navy, though it was also used by the Royal Australian Air Force. That explains why our favorite Aussie overlanders are checking one out at a museum somewhere in Australia. The YouTube description says this is at The Beck Museum. It doesn’t specify whether the aircraft in the video are on display or are awaiting restoration and there isn’t much information online regarding The Beck Museum.
The P-2 has quite a bit of history between Australia and the U.S. The third production P2V-1 was used to set an endurance record for piston powered aircraft that stood from 9 September 1946 until the Rutan Voyager surpassed it during its circumnavigation of the globe in 1986. For that voyage the aircraft was fitted with extra fuel tanks and manned by a crew of four and a kangaroo.
The P-2 was the predecessor of the P-3 Orion and they served alongside each other for about 20 years before the Neptunes retirement.