Have they determined what Mark(s) of Spit these are? I thought they were late war examples buried as the RAF withdrew with the end of hostilities.
I don't think the British had a lot of Spitfires, if any, on the Burma front in 1941-1942. They were using obsolete aircraft such as the Brewster Buffalo fighter and the Vildebeest, a biplane bomber which had entered service in 1928. They were aided by US fliers, flying P-40's, from the American Volunteer Group, later the Fourteenth Air Force, which was based in China.
AFAIK, they’re all Mk 14’s.
If you google this subject you’ll find other articles referring to very late-Mark Spits. Cannon-armed with Rolls-Royce Griffin engines. These would have been very nasty ground-attack ships.
Late in the war the Japanese invaded India. I think that these planes were buried around that time when the air-strips were under threat of being overrun.