The airframes were still in crates, so I'd guess the engines were not installed. I think the chances of the airframes or engines surviving in rebuildable condition are slim at best. They were buried under mud in the Burmese jungle, not some desert. The moisture they've been subjected to will not have done any good. And who knows what, besides water, is in that mud that could attack the metals. If the pH is significantly off from 7.0 that will only accelerate any corrosion.