Back in the mid 1990's I visted the very area of Irian Jaya that you are about to explore. In the area of Jayapura (then Hollandia) the USAAF had three airfields clustered fairly close to one another ( Sentani, Hollandia, and Cyclops). Sentani is now the Intl airport, Cyclops was consumed by the nearby town and the remains of Hollandia are readily visible. Actually when you fly into Sentani sit on the RH side of the A/C with camera in hand. You get about a 10 sec view of the field before your plane touches down at Sentani. I was in a Merpati airways DC-9 ..so its quick! But you can explore th field on foot. Go early in the morning when its still cool. See if you can find a bicycle.
I did go up to Wamena (on a Merpati Twin Otter) but there was really nothing there of note at the time. I am not sure if that field is a WWII era strip or not. I sorta feel that it wasn't.
I also was at Biak where there were three contiguous airfields (Sorido, Mokmer and Boroke). As you probably well know these fields were a large dumping ground for B-24's, B-25, A-20, P-38 et.al. following the war. There are no aircraft left whatsoever. Not even a rivet. Sorido became a military barracks area for the Dutch ( now the Indonesian navy), Mokmer is the Intl airport and Boroke was redeveloped by the Dutch into a military airfield and was in derelict condition..there was a derelict Hawker Hunter there. For post WWII photos of the Biak area go to
www.biak.nl and click on 'fotos' its all written in Dutch but you can worm your way thru. Lots of photos...it'll make you sick to see all those A/C crunched in on each other.
There is one field in the Biak area that is of interest that being Owi Island ..just a couple of miles off of the coast. I had some natives paddle me there in an outrigger canoe. There is a lot of WWII junk laying around the island...actually a lot of junk but no airplanes. You would need a couple of days to really explore it. A small native community is there as well. Be sure to take water with you!! It's worth the trip.
Check out the Biak area in advance using google.earth as it will put it all in perspective for you. BTW, on google.earth you can see the Hawker Hunter along the west side of a hanger bldg!
I think it would be of interest to visit Wadke Island and Middleburg Island which were big airbases as well. They are hard to get to and would require the charter of a boat. They are along the north coast of Irian Jaya.
That's all I can add at this time. Have a good trip.
JohnV