I know someone who could write that book. Esther Balint... she was a beautiful teenager growing in the melee of that place.
It looks like she is a singer now...
http://www.eszterbalint.com/eb_index.html
Bio of SQUAT here, if you can read the grey type
http://www.eszterbalint.com/bio.html
Squat seems to have been eaten by the Fales Library...
I recollect when they got the news their 23rd Street building was sold, to make way for a multiplex movie theater. It was such an enormous degradation. They couldn't believe such a thing could happen in New York City. A CHAIN movie theater... replacing a LIVING THEATER of original plays. The shock was enormous.
And then everyone just did another line.
[Sorry to be cynical but the place did turn into a drug den.]