Well, I'm in my 40's and from what I remember of the 70's at least in regard to being gay, is that you're right, it was hidden, totally. There may have been sections of the community that were hedonistic enough to accept being gay, but it wasn't spoken about in polite company. Not where I lived anyway. I still credit experiencing my teenage years in that era as the time when my true self was stifled. I specifically remember having a crush on a girl that I talked myself out of because it was 'wrong' according to my peers. I agree, reading about people's experiences in those decades would be really interesting.