I read in an article they are Mk14's and it's actually just 16 aircraft with a further 4 only potential, quite amazing story on how the chap came to start looking for these things, he overheard a group of US veterans talking about weird stuff they did during the war and one guy mentioned burying these spits, the story sounds like it's gone beyond just speculation, apparently this guy has made a borehole to get cameras to look at the crates and they look fine, the location is secret.
TOAD the spelling you are looking for is Cosmoline....but that stuff was really for preserving firearms
http://www.telegraph.co.uk/travel/destinations/asia/burma/9204921/British-farmers-quest-to-find-lost-Spitfires-in-Burma.html