To translate the word with Kommunalisierung would't make any sense, because the reader must have an understanding of the time and the usage of the word. If someone uses the word nowadays it means that the commune (the city or village) becomes resposable for the subject.
The commune is in this understanding is the gouverment.
But in those days, at end of the sixties, the term commune had been used differntly even in Germany (cf. http://en.wikipedia.org/wiki/Kommune_1
The commune in this sense are the citizens, the people.
The director of the museum has a totally inacceptable power. He or she defines, what art is, by bying works of artitst.
Instead of this the authors demand something like a council, a board or a committee to make this kind of decisions.
Therefore I like to translate it with: eine Demokratisierung durch eine Vergesellschaftung.
But if you belong to right wing of the Republican Party, communism might be the adaquate translation :-)))