Guys I work in aviation and in my younger days worked in PNG for a few years. And scuba dived a fair bit of the region with war wrecks being a favourite. Amongst other military aviators in the family a relative was KIA in a P40M in the nearby Solomons in 1943, so I've been into SW Pacific WW2 history & warbirds nut pretty much my whole adult life.
I regularly went searching for and looked over wrecks in both countries and there are plenty of them, including a few P38's. With the forestry, mining and palm oil business and the road building going on they are discovering wrecks from time to time and there are hundreds still missing...
I love the Alison V12's and have spent many hours reading books and manuals in them and drooling over them at collectors and museums. Guys I knew who maintained them in modern day warbird collections seemed to prefer them to RR merlins too. Being less cluttered, holding tune longer and basically being a nicer design from an engineering standpoint. My late P40 relative's wingman told me the guys trusted the Allison's to get them home on their long overwater / jungle patrols. Easy to fly and didn't break, were the words he used from memory. I'd do allot to have one in my barn!
The best P38 I saw in PNG was sitting on gas drums at Kiunga Aviation at Nadzab (the "new" Lae airport), owned by local pilot Richard Leahy. All complete, definitely rebuildable airframe with not too much corrosion, couple of bullet holes in the nose and you could still read the writing etc. He collected a bunch of P39's and a few P38's & P40's in the 1970's, when few people seemed to care, and many got sold overseas. You do find the odd engine around too. There were a few Alison's V1710's in a dump in the central Solomon's when I was last there, mostly F3R variants from P40's from memory although I think there was a P39 motor too. The easily accessible wrecks were pretty much all either taken by scrap dealers post war, or by collectors up until the mid 1970's. A couple went to museums. What's left is either too far gone or undiscovered. Plenty of it lying around though if you want to visit. The Solomons is like a rubbish dump of war in some places. Rusting bits and pieces just lying in the grass etc and plenty of wreckage decaying in lagoons. The only sad thing for me is that many are just rotting in open air "museums" and soon will be completely gone. There have been grand plans for western style storage facilities but like many things in these places, it all comes to naught. The best result seems to be when an interested country's national museum does a 1 for 1 deal, taking 2 out to restore and giving one back to the PNG government to display etc. They just can't manage it in their own...
But if you are thinking of doing an Indiana Jones and going to grab one you'll probably be disappointed. If you're are lucky (and rich) enough to find something, beware - local laws prevent removal without government approval and the resident tribal big men always want big $$ too. Mostly the ones found are completely rotten, but there are still some missing in the highlands where conditions aren't so humid or salty. However as many of you probably know, they are like rare sports / muscle cars these days, you can build one from scratch for less than they sell for so all most want is a good build plate and engine tag etc...
And there's still some Alison parts being made today! The Reno races and restorers keep the demand going... :-) Ooops, I have gone on a bit.. Apologies.