The location here is the burial site of the victims (near the plane crash site) given by the US Army at 3 degrees and 51 min. S and 139 degrees and 1 min. E. The small valley the 3 survivors walked (within the larger Baliem Valley) was probably to the south of this location but this should be verified.
The Gremlin Special was a Douglas C-47 Skytrain that crashed during a sightseeing flight over the Shangri-La valley in New Guinea in 1945. The recovery of the three survivors from an isolated valley surrounded by mountains, enemy troops, and native inhabitants made world-wide news at the time and is the subject of the 2011 book Lost in Shangri-La by author Mitchell Zuckoff.