The buildings on that block and the blocks nearby were all build since then. It's possible that the building in question was torn down and replaced by housing.
I began teaching in the NYC public schools in 1985. The older teachers in the school said that what was then called the NYC Board of Education tore down a number of schools during the NYC Fiscal Crisis of the late 1970s, due to a lack of money and a (then) dwindling student population.
Indeed, as a teacher, I have seen the population of the NYC public schools grow far larger in the years that I taught (I began in 1985 and I just retired this past June. I taught for over 25 years, because I took time off to become a parent.) When I began teaching, the NYC public schools had a little more than 900,000 students. By the tine I retired that figure was over 1.1 million!
Today, they are BUILDING new school buildings. But back in the late 70s, they were tearing them down. Sort of sad, don't you think?