In the past year or so China found a huge poison gas dump left behind by Japan.
Also on the B-29 Yahoo group theres a retired AF General Earl Johnson. He was stationed on Guam during WWII and stationed there again as a B-52 wing commander in Vietnam. He said they would regularly raid a known WWII bomb dump and load old WWII 500lb bombs on B-52's destined for North Vietnam.
I also know another guy, Bob Mann, from that group whom I have met, he lives a few miles from my college apartment. He was on Guam in the Korean War doing weather recon. They found (and he has pics too) a huge dump of left over R-3350's from WWII. They were packed in crates and still in cosmoline. Since the weather service B-29's were the redheaded stepchild of the Air Force at the time they didnt get all the required materials they needed because almost all of it was sent to Japan or Okinawa for the B-29's there. So he said they would frequently raid the dump and find the parts they needed. He said each time they did so they were sure to remove the ID tag and replace it with the newer tag on their B-29 so everything matched. Popular items were magnetos, fuel injection pumps and just about all engine accessories.
Bob Mann also has the most comprehensive list of everything B-29 known. I've been to his house and its a complete plethora of B-29 material. He also has a list of each and every B-29 made, their crews, missions, markings, modifications, and their eventual demise. It is truly one of the greatest works I have ever seen!!! He also recently published a book regarding all that stuff... although to a lesser extent than all the actual information he could have put in there. If he put everything he had it would be volumes.