Musing over the possibility that there must be survivors with information about fakery; they may not even know it. (There may be diaries or recorded notes, for that matter).
*Any survivors from the USS Indianapolis (assuming it really was this ship that carried the two supposed bombs to the Marianas)? Even though it was sunk on the return voyage, some sailors survived. Maybe they have stories? Fifty-five years ago, but there could be survivors say 75 years old and up
*As with the 'moon landings' there must be many film makers, studio people, film editors, special effects people who worked on the fake films. They'd be about 60 years older, of course...
*There must have been legal contracts - non-disclosure etc; maybe there are lawyers - and police, military police etc - with information!
*There must have been people who paid for, engineered and built etc the centrifuges and what have you of the Manhattan Project...
*There must have been newspaper, radio, magazine editors who were told what stories they were to publish.
*There may be surviving doctors/ researchers with experience in radiation generally; and who had been to Japan.
*Maybe there are still aircraftmen from the Mariana airstrips - after all huge numbers of bombs were dropped by huge numbers of planes.
If we can judge by the 'Holocaust', the 'Moon Landings', and 9/11 few people are willing to put themselves forward - and if they did they would no doubt be suppressed. But there are some encouraging signs, mostly Internet-based.