The hunt is on for at least 36, and possibly up to 60 unassembled, unused and crated Spitfires buried by the RAF in Burma after the end of the war. The team hunting these lost aircraft seem pretty sure that they have found one site on the airport near Rangoon which was an RAF aerodrome at the time. More details from the BBC website (UK only) at this link: http://www.bbc.co.uk/news/uk-20515659
I think you've asked "What took them so long?" It's fair to say that many people, both Burmese and ex-RAF personnel knew of the approximate locations, but don't forget that trees and vegetation grows, roads and other infrastructure gets built so the general appearance of any environment can change quite dramatically. And, of course the number of people who knew is dwindling by the day. Added to that, Burma has been a "closed country" for many years; it's only very recently; since the release from house-arrest of Aung San Suu Kyi that the barriers have come down which has allowed the archaeologists to conduct their geo-physical surveys of the areas where these Spitfires are thought to be. By all accounts, one of the leaders of the search team has been fairly sure of the location for about sixteen years, but for all the political reasons was unable to do anything about it.
